mesa: enable virgl driver for qemux86/qemux86-64

virgl driver should be enabled for qemux86/qemux86-64 machines, or else
it will cause runtime issue due to virtio_gpu driver missing.

(From OE-Core rev: 5f143ceb1fac06ac84370ceb0cf0fba656effdf8)

Signed-off-by: Ming Liu <liu.ming50@gmail.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-graphics/mesa/mesa.inc

@@ -91,6 +91,8 @@ GALLIUMDRIVERS_LLVM33_ENABLED = "${@oe.utils.version_less_or_equal('MESA_LLVM_RE
 GALLIUMDRIVERS_LLVM = "r300,svga,nouveau${@',${GALLIUMDRIVERS_LLVM33}' if ${GALLIUMDRIVERS_LLVM33_ENABLED} else ''}"
 GALLIUMDRIVERS_append_x86 = "${@bb.utils.contains('PACKAGECONFIG', 'gallium-llvm', ',${GALLIUMDRIVERS_LLVM}', '', d)}"
 GALLIUMDRIVERS_append_x86-64 = "${@bb.utils.contains('PACKAGECONFIG', 'gallium-llvm', ',${GALLIUMDRIVERS_LLVM}', '', d)}"
+GALLIUMDRIVERS_append_qemux86 = ",virgl"
+GALLIUMDRIVERS_append_qemux86-64 = ",virgl"
 # keep --with-gallium-drivers separate, because when only one of gallium versions is enabled, other 2 were adding --without-gallium-drivers
 PACKAGECONFIG[gallium]      = "--enable-texture-float --with-gallium-drivers=${GALLIUMDRIVERS}, --without-gallium-drivers"
 MESA_LLVM_RELEASE ?= "6.0"