gitconfig: Use the right make executable in git hooks

When installing git hooks through $(MAKE) gitconfig,
make knows itself (and is a GNU make). So let it splice
itself into hooks where necessary by replacing %MAKE%.

Change-Id: Iaf778bfa3f17a8fe31312f871571ed89a9de5385
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/10018
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
diff --git a/Makefile.inc b/Makefile.inc
index d0a292c..c1e7def 100644
--- a/Makefile.inc
+++ b/Makefile.inc
@@ -418,7 +418,7 @@
 	for hook in commit-msg pre-commit ; do                       \
 		if [ util/gitconfig/$$hook -nt .git/hooks/$$hook -o  \
 		! -x .git/hooks/$$hook ]; then			     \
-			cp util/gitconfig/$$hook .git/hooks/$$hook;  \
+			sed -e "s,%MAKE%,$(MAKE),g" util/gitconfig/$$hook > .git/hooks/$$hook;  \
 			chmod +x .git/hooks/$$hook;		     \
 		fi;						     \
 	done