The address of OpRegion is not 4KB aligned,
if the OpRegion + extended VBT size is 16KB,
then it will take up to 5 physical pages in host.
So update the OpRegion size to 20KB
to expose the whole OpRegion to guest.
Tracked-On: #6270
Signed-off-by: Liu,Junming <junming.liu@intel.com>
Acked-by: Wang, Yu1 <yu1.wang@intel.com>