drm/amdgpu/display: Use wm_table.entries for dcn301 calculate_wm

[Why]
For DGPU Navi, the wm_table.nv_entries are used. These entires are not
populated for DCN301 Vangogh APU, but instead wm_table.entries are.

[How]
Use DCN21 Renoir style wm calculations.

Signed-off-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Zhan Liu <zhan.liu@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Zhan Liu <zhan.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>