drm/i915/display: convert W/As in intel_pmdemand.c to new framework

drm/i915/display: convert W/As in intel_pmdemand.c to new framework

Convert the low-hanging fruits of workaround checks to the workaround
framework.  Instead of having display structure checks for the
workarounds all over, concentrate the checks in intel_display_wa.c.

Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://patch.msgid.link/20260305100100.332956-14-luciano.coelho@intel.com
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>