automake: build all drivers but vc4 during distcheck

vc4 conflicts with ilo, when build on x86 as it's build for emulation
purposes. In that mode a i965-like symbol is exported by vc4, which
conflicts with the ilo one in the gallium-dri megadriver.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
diff --git a/Makefile.am b/Makefile.am
index 9f49ce6..149610c 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -32,7 +32,9 @@
 	--enable-vdpau \
 	--enable-xa \
 	--enable-xvmc \
-	--with-egl-platforms=x11,wayland,drm
+	--with-egl-platforms=x11,wayland,drm \
+	--with-dri-drivers=i915,i965,nouveau,radeon,r200,swrast \
+	--with-gallium-drivers=i915,ilo,nouveau,r300,r600,radeonsi,freedreno,svga,swrast
 
 ACLOCAL_AMFLAGS = -I m4