drm/i915/vrr: Stop writing VRR_CTL_IGN_MAX_SHIFT for MTL onwards

drm/i915/vrr: Stop writing VRR_CTL_IGN_MAX_SHIFT for MTL onwards

According to Bspec VRR_CTL_IGN_MAX_SHIFT doesn't exist for MTL and
onwards. On LunarLake and onwards Bit 30 is "Mask Block PkgC" instead. Stop
writing the bit for MeteorLake and onwards

v2: "Ignore Max Shift" bit doesn't exist on MeteorLake either

Bspec: 50508, 68925
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://lore.kernel.org/r/20250409054909.968531-1-jouni.hogander@intel.com