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>
1 file changed