[source] powerpc: boot: fix build with parallel make

[LEDE Commits]

jow pushed a commit to source.git, branch master:
https://git.lede-project.org/38a8cea063ee25971bc5a9e8842edda280ed8513

commit 38a8cea063ee25971bc5a9e8842edda280ed8513
Author: Jo-Philipp Wich <jo at mein.io>
AuthorDate: Wed Jan 4 10:42:28 2017 +0100

    powerpc: boot: fix build with parallel make
    
    The powerpc boot wrapper Makefile is not parallel build safe, causing fixdep
    to fail reading dependency files of the addnote, hack-coff and mktree
    utilities when concurrently building different image targets.
    
    A typical failure looks like:
    
          Building modules, stage 2.
          HOSTCC  arch/powerpc/boot/addnote
          HOSTCC  arch/powerpc/boot/hack-coff
          DTC     arch/powerpc/boot/taishan.dtb
          HOSTCC  arch/powerpc/boot/addnote
          HOSTCC  arch/powerpc/boot/hack-coff
          MODPOST 800 modules
        fixdep: error opening depfile: arch/powerpc/boot/.hack-coff.d: No such file or directory
        scripts/Makefile.host:91: recipe for target 'arch/powerpc/boot/hack-coff' failed
        make[5]: *** [arch/powerpc/boot/hack-coff] Error 2
        make[5]: *** Waiting for unfinished jobs....
        fixdep: error opening depfile: arch/powerpc/boot/.addnote.d: No such file or directory
        scripts/Makefile.host:91: recipe for target 'arch/powerpc/boot/addnote' failed
        make[5]: *** [arch/powerpc/boot/addnote] Error 2
        rm arch/powerpc/boot/taishan.dtb
        arch/powerpc/Makefile:263: recipe for target 'cuImage.taishan' failed
        make[4]: *** [cuImage.taishan] Error 2
        make[4]: *** Waiting for unfinished jobs....
    
    Add a GNU make specific .NOTPARALLEL pseudo rule to enforce sequential building
    of the addnote, hack-coff and mktree executables.
    
    Signed-off-by: Jo-Philipp Wich <jo at mein.io>
---
 .../900-bootwrapper-parallel-make-fix.patch        | 45 ++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/target/linux/ppc44x/patches-3.18/900-bootwrapper-parallel-make-fix.patch b/target/linux/ppc44x/patches-3.18/900-bootwrapper-parallel-make-fix.patch
new file mode 100644
index 0000000..313347c
--- /dev/null
+++ b/target/linux/ppc44x/patches-3.18/900-bootwrapper-parallel-make-fix.patch
@@ -0,0 +1,45 @@
+From: Jo-Philipp Wich <jo at mein.io>
+Date: Wed, 4 Jan 2017 10:35:00 +0100
+Subject: [PATCH] powerpc: boot: fix build with parallel make
+
+The powerpc boot wrapper Makefile is not parallel build safe, causing fixdep
+to fail reading dependency files of the addnote, hack-coff and mktree
+utilities when concurrently building different image targets.
+
+A typical failure looks like:
+
+      Building modules, stage 2.
+      HOSTCC  arch/powerpc/boot/addnote
+      HOSTCC  arch/powerpc/boot/hack-coff
+      DTC     arch/powerpc/boot/taishan.dtb
+      HOSTCC  arch/powerpc/boot/addnote
+      HOSTCC  arch/powerpc/boot/hack-coff
+      MODPOST 800 modules
+    fixdep: error opening depfile: arch/powerpc/boot/.hack-coff.d: No such file or directory
+    scripts/Makefile.host:91: recipe for target 'arch/powerpc/boot/hack-coff' failed
+    make[5]: *** [arch/powerpc/boot/hack-coff] Error 2
+    make[5]: *** Waiting for unfinished jobs....
+    fixdep: error opening depfile: arch/powerpc/boot/.addnote.d: No such file or directory
+    scripts/Makefile.host:91: recipe for target 'arch/powerpc/boot/addnote' failed
+    make[5]: *** [arch/powerpc/boot/addnote] Error 2
+    rm arch/powerpc/boot/taishan.dtb
+    arch/powerpc/Makefile:263: recipe for target 'cuImage.taishan' failed
+    make[4]: *** [cuImage.taishan] Error 2
+    make[4]: *** Waiting for unfinished jobs....
+
+Add a GNU make specific .NOTPARALLEL pseudo rule to enforce sequential building
+of the addnote, hack-coff and mktree executables.
+
+Signed-off-by: Jo-Philipp Wich <jo at mein.io>
+
+--- a/arch/powerpc/boot/Makefile
++++ b/arch/powerpc/boot/Makefile
+@@ -194,6 +194,8 @@ wrapper		:=$(srctree)/$(src)/wrapper
+ wrapperbits	:= $(extra-y) $(addprefix $(obj)/,addnote hack-coff mktree) \
+ 			$(wrapper) FORCE
+ 
++.NOTPARALLEL: $(addprefix $(obj)/,addnote hack-coff mktree) $(wrapper)
++
+ #############
+ # Bits for building various flavours of zImage
+