drm/amd/display: Update DCN401 path for cursor offload

drm/amd/display: Update DCN401 path for cursor offload

[Description]
The DCN401 cursor offload path needs to take into account
use_mall_for_cursor, and also need to ensure the dcn32
function assigns the cursor cache fields (DCN401 uses the
dcn32 implementation).

Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Alvin Lee <Alvin.Lee2@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>