drm/i915/gvt: Fix BDW command parser regression

On BDW new Windows driver has brought extra registers to handle for
LRM/LRR command in WA ctx. Add allowed registers in cmd parser for BDW.

Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Yan Zhao <yan.y.zhao@intel.com>
Cc: stable@vger.kernel.org
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Colin Xu <colin.xu@intel.com>
Fixes: 73a37a43 ("drm/i915/gvt: filter cmds "lrr-src" and "lrr-dst" in cmd_handler")
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20210414084813.3763353-1-zhenyuw@linux.intel.com