Merge branch 'gallium-drm-driver-drescriptor'

Conflicts:
	src/gallium/state_trackers/egl/x11/native_dri2.c
	src/gallium/state_trackers/egl/x11/native_x11.c
	src/gallium/state_trackers/egl/x11/native_x11.h
	src/gallium/state_trackers/xorg/xorg_driver.c
	src/gallium/winsys/radeon/drm/radeon_drm.c