[source] u-boot.mk: pass HOSTCC and HOST_CFLAGS into the build

[LEDE Commits]

nbd pushed a commit to source.git, branch master:
https://git.lede-project.org/68139cc0e819b5f654c4f78468049eef035d28f7

commit 68139cc0e819b5f654c4f78468049eef035d28f7
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Thu Mar 16 09:01:56 2017 +0100

    u-boot.mk: pass HOSTCC and HOST_CFLAGS into the build
    
    Cuts build time on Mac OS X in half by avoiding repeated $(shell) calls
    from the build system
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 include/u-boot.mk                  | 5 +++++
 package/boot/uboot-lantiq/Makefile | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/include/u-boot.mk b/include/u-boot.mk
index 0c28653..4b3ff69 100644
--- a/include/u-boot.mk
+++ b/include/u-boot.mk
@@ -40,6 +40,11 @@ endef
 
 TARGET_DEP = TARGET_$(BUILD_TARGET)$(if $(BUILD_SUBTARGET),_$(BUILD_SUBTARGET))
 
+UBOOT_MAKE_FLAGS = \
+	HOSTCC="$(HOSTCC)" \
+	HOSTCFLAGS='$(HOST_CFLAGS) $$$$(HOSTCPPFLAGS)' \
+	HOSTLDFLAGS=""
+
 define Build/U-Boot/Target
   $(eval $(call U-Boot/Init,$(1)))
   $(eval $(call U-Boot/Default,$(1)))
diff --git a/package/boot/uboot-lantiq/Makefile b/package/boot/uboot-lantiq/Makefile
index b16e7cd..94b604a 100644
--- a/package/boot/uboot-lantiq/Makefile
+++ b/package/boot/uboot-lantiq/Makefile
@@ -366,6 +366,8 @@ define Build/Prepare
 	$(call CompressVR9Firmware,22f,2)
 endef
 
+UBOOT_MAKE_FLAGS :=
+
 ifeq ($(SUBTARGET),xway)
   SOC:=danube
 else