drm/i915/gvt: Allow F_CMD_ACCESS on mmio 0x21f0

The newly updated guest driver could program 0x21f0 via lri and srm,
without F_CMD_ACCESS flag cmd parser will stop parser reset cmd.
0x21f0 applies to BDW, SKL, KBL, BXT and CFL.
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Colin Xu <colin.xu@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

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

@@ -2799,6 +2799,7 @@ static int init_broadwell_mmio_info(struct intel_gvt *gvt)
 	MMIO_DFH(_MMIO(0xe2a0), D_BDW_PLUS, F_CMD_ACCESS, NULL, NULL);
 	MMIO_DFH(_MMIO(0xe2b0), D_BDW_PLUS, F_CMD_ACCESS, NULL, NULL);
 	MMIO_DFH(_MMIO(0xe2c0), D_BDW_PLUS, F_CMD_ACCESS, NULL, NULL);
+	MMIO_DFH(_MMIO(0x21f0), D_BDW_PLUS, F_CMD_ACCESS, NULL, NULL);
 	return 0;
 }