Fix PciHostBridge driver to return success for EfiPciHostBridgeEndEnumeration to fix OVMF boot no display issue.

Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14498 6f19259b-4bc3-4df7-8a09-765794883524