drm/i915: Move display related definitions to dedicated header

drm/i915: Move display related definitions to dedicated header

We already have separate files for display related code, there
is no reason to keep all display definitions in master header.

Signed-off-by: Michal Wajdeczko <[email protected]>
Cc: Chris Wilson <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: Joonas Lahtinen <[email protected]>
Reviewed-by: Chris Wilson <[email protected]>
Acked-by: Rodrigo Vivi <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
[ickle: quieten checkpatch]
Signed-off-by: Chris Wilson <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]