drm/amd/display: Align LSDMA commands fields

[WHY]
DC LSDMA functions had to remember to extract 1 from several fields
to be compliant with DMUB LSDMA commands interface.
Now this logic is moved to DMUB.

[HOW]
Moved extraction by 1 in several fields of LSDMA commands to DMUB.
Changed DC to not do it.

Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Signed-off-by: Rafal Ostrowski <rostrows@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>