drm/amd/display: Drop uncessary OTG lock check

The OTG_MASTER_UPDATE_LOCK_SEL is used for GSL and OTGs in the same
group for selecting the OTG_MASTER_UPDATE_LOCK from the same OTG. At
some point, it a check was added to see if OTG is running or not, which
is not necessary, and for this reason, this commit dropped that check.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>