HDMI and DisplayPort sequences states that audio and PSR should be
disabled before planes are disabled.
Not following it did not caused any problems up to Alderlake-P but
for this platform it causes underruns during the PSR2 disable
sequence.

Specification don't mention that DRRS should be disabled before planes
but it looks safer to switch back to the default refresh rate before
following with the rest of the pipe disable sequence.

BSpec: 49191
BSpec: 49190
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210726181559.80855-1-jose.souza@intel.com