drm/i915/gvt: Replace duplicated code with exist function

Use the exist function intel_gvt_ggtt_validate_range to replace
these duplicated code that do the same thing.

Signed-off-by: Ping Gao <ping.a.gao@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
1 file changed