i965: Add XRGB8888 format to intel_screen_make_configs

i965: Add XRGB8888 format to intel_screen_make_configs

Some application, such as drm backend of weston, uses XRGB8888 config as
default. i965 doesn't provide this format, but before commit 65c8965d,
the drm platform of EGL takes ARGB8888 as XRGB8888. Now that commit
65c8965d makes EGL recognize format correctly so weston won't start
because it can't find XRGB8888. Add XRGB8888 format to i965 just as
other drivers do.

Cc: mesa-stable@lists.freedesktop.org
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89689
Signed-off-by: Boyan Ding <boyan.j.ding@gmail.com>
Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>