libva: fix gcc6 build

Avoid an out-of-tree source file va_drm_utils.c by creating a
symlink from va/wayland/va_drm_utils.c to var/drm/va_drm_utils.c
This fixes the autotools with gcc6 wrong dependency for this file.

srcpkgs/libva/patches/fix-wayland_makefile_am.patch

@@ -0,0 +1,28 @@
+--- va/wayland/Makefile.am	2016-08-25 04:42:40.000000000 +0200
++++ va/wayland/Makefile.am	2016-09-12 18:05:59.410106843 +0200
+@@ -24,6 +24,7 @@
+ 	-DLINUX			\
+ 	-I$(top_srcdir)		\
+ 	-I$(top_srcdir)/va	\
++	-I$(top_srcdir)/va/drm	\
+ 	$(WAYLAND_CFLAGS)	\
+ 	$(DRM_CFLAGS)		\
+ 	$(NULL)
+@@ -32,7 +33,7 @@
+ 	va_wayland.c		\
+ 	va_wayland_drm.c	\
+ 	va_wayland_emgd.c	\
+-	$(top_srcdir)/va/drm/va_drm_utils.c \
++	va_drm_utils.c		\
+ 	$(NULL)
+ 
+ source_h = \
+@@ -58,7 +59,7 @@
+ 
+ # Wayland protocol
+ va_wayland_drm.c: $(protocol_source_h)
+-%-client-protocol.h : %.xml
++wayland-client-protocol.h : wayland.xml
+ 	$(AM_V_GEN)$(WAYLAND_SCANNER) client-header < $< > $@
+ 
+ EXTRA_DIST = \

srcpkgs/libva/template

@@ -1,7 +1,7 @@
 # Template file for 'libva'
 pkgname=libva
 version=1.7.2
-revision=1
+revision=2
 build_style=gnu-configure
 configure_args="--disable-static --enable-x11 --disable-egl --disable-glx"
 hostmakedepends="automake pkg-config libtool"
@@ -14,6 +14,8 @@ distfiles="${FREEDESKTOP_SITE}/vaapi/releases/libva/libva-${version}.tar.bz2"
 checksum=5dd61cf16a5648b680e6146a58064e93be11bf4e65a9e4e30f1e9cb8ecfa2c13
 
 pre_configure() {
+	# Create a symbolic link to avoid out of source tree compiling
+	ln -sf ../drm/va_drm_utils.c va/wayland/va_drm_utils.c
 	autoreconf -fi
 }
 post_install() {