Don't check for Xinerama.
Don't check for Xinerama.

It doesn't seem to be used anywhere, so don't require it.

CC: Jerome Glisse <0620d428a1bd3756b1319066bf466b3b8be0b2b2@redhat.com>
CC: Alex Deucher <bf84f557a1e54fd62cd73c6847f7d9df60e9fbef@gmail.com>
CC: Dave Airlie <f2295d84e358395675bc8031be58672073ae065e@redhat.com>
Signed-off-by: Matt Turner <789b315743a28dd066a4ba1459c35951c291d8a6@gmail.com>

patjak/xf86-video-gma500,patjak/xf86-video-gma500,wzyy2/xf86-video-modesetting,wzyy2/xf86-video-modesetting