drm/amd/display: Fix warning storm on Raven2

[Why]
Wrong index for pstate debug test register

[How]
Add correct index value for dcn1_01 in hubbub1_construct()

Signed-off-by: Hersen Wu <hersenxs.wu@amd.com>
Signed-off-by: Roman Li <Roman.Li@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>