drm/i915/psr: LunarLake PSR2_CTL[IO Wake Lines] is 6 bits wide

On LunarLake  PSR2_CTL[IO Wake Lines] contains now bit 13:18. Take this
into account when enabling PSR2_CTL.

Bspec: 69885

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240517073005.2414293-3-jouni.hogander@intel.com