Add a workaround to fix BS (blank start) to BS jitter issues on MST
links when FEC is enabled. Neither Bspec requires this nor Windows
clears the WA when disabling the output - presumedly because
CHICKEN_MISC_3 gets reset after disabling the pipe/transcoder - so
follow suit.

Bspec: 50050, 55424
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240129175533.904590-2-imre.deak@intel.com