Set up 3rdparty/libgfxinit

`libgfxinit` is a SPARK library for graphics modesetting. It supports
Intel integrated graphics only, strictly speaking, the Core i processor
line.

Change-Id: Idf4b0e5fbf37a5d974075b2e44d1fa16dc428da3
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/16949
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

.gitmodules

@@ -18,3 +18,6 @@
 [submodule "libhwbase"]
 	path = 3rdparty/libhwbase
 	url = ../libhwbase.git
+[submodule "libgfxinit"]
+	path = 3rdparty/libgfxinit
+	url = ../libgfxinit.git

3rdparty/libgfxinit

@@ -0,0 +1 @@
+Subproject commit 83693c8d7d87f5cebe120abdf25951c9e212b319

Makefile.inc

@@ -568,7 +568,7 @@ gitconfig:
 		fi;						     \
 	done
 	# Now set up thehooks for 3rdparty/
-	for hooks in .git/modules/{3rdparty/blobs,libhwbase}/hooks; do					\
+	for hooks in .git/modules/{3rdparty/blobs,libhwbase,libgfxinit}/hooks; do			\
 		if [ -d $$hooks -a									\
 		\( util/gitconfig/commit-msg -nt $$hooks/commit-msg -o					\
 			! -x $$hooks/commit-msg \) ]; then						\
@@ -576,7 +576,7 @@ gitconfig:
 			chmod +x $$hooks/commit-msg;							\
 		fi											\
 	done
-	for d in 3rdparty/{blobs,libhwbase}; do					\
+	for d in 3rdparty/{blobs,libhwbase,libgfxinit}; do			\
 		if [ -d $$d ]; then						\
 			(cd $$d;						\
 			 git config remote.origin.push HEAD:refs/for/master);	\