drm/i915/psr: LunarLake IO and Fast Wake time line count maximums are 68

On LunarLake maximum for IO and Fast Wake time line counts are 68: 6 bits +
5 lines added by the HW. Take this into account in calculation and when
writing the IO Wake lines.

v2: maximum line count is 68 (6 bits + 5 lines added by HW)

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240517073005.2414293-2-jouni.hogander@intel.com