drm/i915/gvt: Add one missing MMIO handler for D_SKL_PLUS

_PLANE_CTL_3_A, _PLANE_CTL_3_B and _PLANE_SURF_3_A are handled, but
miss _PLANE_SURF_3_B.
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Colin Xu <colin.xu@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200601030457.14002-1-colin.xu@intel.com

drivers/gpu/drm/i915/gvt/handlers.c

@@ -3055,6 +3055,7 @@ static int init_skl_mmio_info(struct intel_gvt *gvt)
 	MMIO_D(_MMIO(0x72380), D_SKL_PLUS);
 	MMIO_D(_MMIO(0x7239c), D_SKL_PLUS);
 	MMIO_D(_MMIO(_PLANE_SURF_3_A), D_SKL_PLUS);
+	MMIO_D(_MMIO(_PLANE_SURF_3_B), D_SKL_PLUS);
 
 	MMIO_D(CSR_SSP_BASE, D_SKL_PLUS);
 	MMIO_D(CSR_HTP_SKL, D_SKL_PLUS);