drm/amd/pm: remove logically dead code

Execution cannot reach this statement: case POWER_STATE_TYPE_BALAN.
Signed-off-by: Jesse Zhang <Jesse.Zhang@amd.com>
Acked-by: Yang Wang <kevinyang.wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/pm/legacy-dpm/legacy_dpm.c

@@ -831,15 +831,6 @@ static struct amdgpu_ps *amdgpu_dpm_pick_power_state(struct amdgpu_device *adev,
 					return ps;
 			}
 			break;
-		case POWER_STATE_TYPE_BALANCED:
-			if (ui_class == ATOM_PPLIB_CLASSIFICATION_UI_BALANCED) {
-				if (ps->caps & ATOM_PPLIB_SINGLE_DISPLAY_ONLY) {
-					if (single_display)
-						return ps;
-				} else
-					return ps;
-			}
-			break;
 		case POWER_STATE_TYPE_PERFORMANCE:
 			if (ui_class == ATOM_PPLIB_CLASSIFICATION_UI_PERFORMANCE) {
 				if (ps->caps & ATOM_PPLIB_SINGLE_DISPLAY_ONLY) {