The PSR code has no business mucking around with the
vblank delay. Currently nothing that depends on knowing
the exact vblank start scanline (eg. vblank evasion)
is aware of this and so will not work correctly.

The w/a seems to be for pre-production hw only, so let's
just nuke it.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230213225258.2127-8-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>