drm/i915: Carve up skl_get_plane_caps()

Split skl_get_plane_caps() into four variants:
skl_plane_caps(), glk_plane_caps(), icl_plane_caps(),
tgl_plane_caps().

Makes it easier to figure out what is actually going on there.

v2: skl_plane_caps() should return u8 not bool

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241010164617.10280-1-ville.syrjala@linux.intel.com


Reviewed-by: Jouni Högander <jouni.hogander@intel.com>