Revert "drm/amdgpu: disable gfxoff for navy_flounder"

This reverts commit ba4e049e.
Newly released sdma fw (51.52) provides a fix for the issue.
Signed-off-by: Jiansong Chen <Jiansong.Chen@amd.com>
Reviewed-by: Kenneth Feng <kenneth.feng@amd.com>
Reviewed-by: Tao Zhou <tao.zhou1@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c

@@ -3610,9 +3610,6 @@ static void gfx_v10_0_check_gfxoff_flag(struct amdgpu_device *adev)
 		if (!gfx_v10_0_navi10_gfxoff_should_enable(adev))
 			adev->pm.pp_feature &= ~PP_GFXOFF_MASK;
 		break;
-	case CHIP_NAVY_FLOUNDER:
-		adev->pm.pp_feature &= ~PP_GFXOFF_MASK;
-		break;
 	default:
 		break;
 	}