Revert "drm/i915/display: Re-add check for low voltage sku for max dp source rate"

Revert "drm/i915/display: Re-add check for low voltage sku for max dp source rate"

This reverts commit b8952a64a2421017d878ee4d610d6fc8191adef6.

With the Parade PS8461E MUX workaround (WaEdpLinkRateDataReload)
implemented we can get finally rid of the is_low_voltage_sku()
check that incorrectly prevents many machines from using the
8.1Gpbs link rate.

Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5272
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6323
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6205
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220902070319.15395-2-ville.syrjala@linux.intel.com
Tested-by: Aaron Ma <aaron.ma@canonical.com>
Tested-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>