i965/screen: Add basic support for rendering 10 bpc/depth 30 framebuffers. (v3)

i965/screen: Add basic support for rendering 10 bpc/depth 30 framebuffers. (v3)

Expose formats which are supported at least back to Gen 5 Ironlake,
possibly further. Allow creation of 10 bpc winsys buffers for drawables.

glxinfo now lists new RGBA 10 10 10 2/0 formats.

v2: Move the BGRA/BGRX1010102 formats before the RGBA/RGBX8888
    32 bit formats, as the code comments require. Thanks Emil!
    Update num_formats from 3 to 5, to keep the special Android
    handling intact.

v3: Use num_formats = ARRAY_SIZE(formats) - 2 as suggested by Tapani,
    to only exclude the last 2 Android formats, add Tapani's r-b.

Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>
Signed-off-by: Marek Olšák <marek.olsak@amd.com>