drm/i915: Eliminate the initial_plane_phys_{smem,lmem}() duplication

initial_plane_phys_lmem() and initial_plane_phys_smem() are
now identical. Remove one of them.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250313140838.29742-11-ville.syrjala@linux.intel.com


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