[source] grub2: add PKG_FIXUP:=autoreconf

[LEDE Commits]

nbd pushed a commit to source.git, branch master:
https://git.lede-project.org/b33845b2da7a02393f0814f161befa6cc2d5da7c

commit b33845b2da7a02393f0814f161befa6cc2d5da7c
Author: Alexandru Ardelean <ardeleanalex at gmail.com>
AuthorDate: Thu Nov 17 18:25:52 2016 +0200

    grub2: add PKG_FIXUP:=autoreconf
    
    Reboot of: a0ea22ac430f91ab045431a79b2e2161e66cd56a
    Reverted: 3c52cbfa53056ded95ae5a7ae27319eafd5a37e5
    
    The host-side build of grub2 requires this sometimes.
    This will re-generate the ./configure script from configure.ac.
    I don't know the conditions of how this reproduces, it just
    sometimes appears, and sometimes doesn't.
    
    Build error
    ```
    <lede-dir>/build_dir/target-x86_64_musl-1.1.15_yogi/host/grub-2.02~beta2/build-aux/missing: line 81: aclocal-1.14: command not found
    WARNING: 'aclocal-1.14' is missing on your system.
             You should only need it if you modified 'acinclude.m4' or
             'configure.ac' or m4 files included by 'configure.ac'.
             The 'aclocal' program is part of the GNU Automake package:
             <http://www.gnu.org/software/automake>
             It also requires GNU Autoconf, GNU m4 and Perl in order to run:
             <http://www.gnu.org/software/autoconf>
             <http://www.gnu.org/software/m4/>
             <http://www.perl.org/>
    Makefile:3962: recipe for target 'aclocal.m4' failed
    ```
    
    Adding PKG_FIXUP adds sanity (i.e. autoreconf is used for host & target
    builds) over just using HOST_FIXUP.
    
    Signed-off-by: Alexandru Ardelean <ardeleanalex at gmail.com>
---
 package/boot/grub2/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/package/boot/grub2/Makefile b/package/boot/grub2/Makefile
index 75f5e82..6b96e0a 100644
--- a/package/boot/grub2/Makefile
+++ b/package/boot/grub2/Makefile
@@ -19,6 +19,7 @@ PKG_SOURCE_URL:=http://alpha.gnu.org/gnu/grub \
 	http://www.nic.funet.fi/pub/gnu/alpha/gnu/grub/
 PKG_HASH:=f6c702b2a8ea58f27a2b02928bb77973cb5a827af08f63db38c471c0a01b418d
 
+PKG_FIXUP:=autoreconf
 HOST_BUILD_PARALLEL:=1
 PKG_BUILD_DEPENDS:=grub2/host