drm/i915: Remove the "INDEX" suffix from PPAT marcos

drm/i915: Remove the "INDEX" suffix from PPAT marcos

Remove the "INDEX" suffix from PPAT marcos as they are bits actually, not
indexes.

Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Cc: Ben Widawsky <benjamin.widawsky@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1505392783-4084-2-git-send-email-zhi.a.wang@intel.com