drm/i915: Allow alternate fixed modes always for eDP

drm/i915: Allow alternate fixed modes always for eDP

Stop considering VBT's static DRRS support when deciding whether
to use alternate fixed modes or not. It looks like Windows more
or less just uses that to decide whether to automagically switch
refresh rates on AC<->battery changes, or perhaps whether to
even expose a control for that in some UI thing. Either way it
seems happy to always use all EDID modes, and I guess the
DRRS/VRR stuff more or less adjusts how said modes get
actually used.

Let's do the same and just accept all the suitable looking
modes from EDID, whether we have DRRS or VRR.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6323
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6484
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220927180615.25476-3-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>