drm/i915/gvt: Refine non privilege register address calucation

The BitField of non privilege register address is only from bit 2 to 25.

v2: use REG_GENMASK instead. (Zhenyu)

Signed-off-by: Gao, Fred <fred.gao@intel.com>
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
1 file changed