drm/i915: make a handful of read-only arrays static const

Don't populate the read-only arrays on the stack but instead make
them static const and signed 8 bit ints. Also makes the object code a
little smaller.  Reformat the statements to clear up checkpatch warning.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220223120923.239867-1-colin.i.king@gmail.com