drm/i915/gvt: Update force-to-nonpriv register whitelist

Host prints below warning message when guest running some application:
"gvt: vgpu(1) Invalid FORCE_NONPRIV write 2754 at 24f0".
"gvt: vgpu(1) Invalid FORCE_NONPRIV write 28a0 at 24f0".

Registers 0x2754 and 0x28a0 are required by guest so add to whitelist.
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

@@ -464,6 +464,8 @@ static i915_reg_t force_nonpriv_white_list[] = {
 	_MMIO(0x2690),
 	_MMIO(0x2694),
 	_MMIO(0x2698),
+	_MMIO(0x2754),
+	_MMIO(0x28a0),
 	_MMIO(0x4de0),
 	_MMIO(0x4de4),
 	_MMIO(0x4dfc),