drm/amdgpu/gmc9: fix VM_L2_CNTL3 programming

Got accidently dropped when 2+1 level support was added.

Fixes: 6a42fd6f ("drm/amdgpu: implement 2+1 PD support for Raven v3")
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c

@@ -182,6 +182,7 @@ static void mmhub_v1_0_init_cache_regs(struct amdgpu_device *adev)
 		tmp = REG_SET_FIELD(tmp, VM_L2_CNTL3,
 				    L2_CACHE_BIGK_FRAGMENT_SIZE, 6);
 	}
+	WREG32_SOC15(MMHUB, 0, mmVM_L2_CNTL3, tmp);
 
 	tmp = mmVM_L2_CNTL4_DEFAULT;
 	tmp = REG_SET_FIELD(tmp, VM_L2_CNTL4, VMC_TAP_PDE_REQUEST_PHYSICAL, 0);