drm/amd/display: Use set_vtotal_min_max to configure OTG VTOTAL

In multiple parts of the DCN code, we write directly to the
OTG_V_TOTAL_* registers in some OPTC functions. Let's avoid it by using
the set_vtotal_min_max.

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>