drm/i915: make array states static const

Don't populate the read-only array states on the stack but instead it
static. Also makes the object code smaller.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210915112702.12783-1-colin.king@canonical.com