automake: add more missing options for make distcheck

Namely - opencl, osmesa (only the gallium flavour as it conflicts with
the classic one), surfaceless egl platform and a couple gallium drivers
(virgl and vc4).

Cc: "11.1 11.2" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
diff --git a/Makefile.am b/Makefile.am
index 5df8bc3..2c06e3a 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -24,19 +24,21 @@
 AM_DISTCHECK_CONFIGURE_FLAGS = \
 	--enable-dri3 \
 	--enable-gallium-tests \
+	--enable-gallium-osmesa \
 	--enable-gbm \
 	--enable-gles1 \
 	--enable-gles2 \
 	--enable-glx-tls \
 	--enable-nine \
+	--enable-opencl \
 	--enable-va \
 	--enable-vdpau \
 	--enable-xa \
 	--enable-xvmc \
 	--disable-llvm-shared-libs \
-	--with-egl-platforms=x11,wayland,drm \
+	--with-egl-platforms=x11,wayland,drm,surfaceless \
 	--with-dri-drivers=i915,i965,nouveau,radeon,r200,swrast \
-	--with-gallium-drivers=i915,ilo,nouveau,r300,r600,radeonsi,freedreno,svga,swrast
+	--with-gallium-drivers=i915,ilo,nouveau,r300,r600,radeonsi,freedreno,svga,swrast,vc4,virgl
 
 ACLOCAL_AMFLAGS = -I m4