drm/radeon: fix typo in trinity tiling setup

Using the wrong union.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/ni.c

@@ -865,7 +865,7 @@ static void cayman_gpu_init(struct radeon_device *rdev)
 
 	/* num banks is 8 on all fusion asics. 0 = 4, 1 = 8, 2 = 16 */
 	if (rdev->flags & RADEON_IS_IGP)
-		rdev->config.evergreen.tile_config |= 1 << 4;
+		rdev->config.cayman.tile_config |= 1 << 4;
 	else
 		rdev->config.cayman.tile_config |=
 			((mc_arb_ramcfg & NOOFBANK_MASK) >> NOOFBANK_SHIFT) << 4;