MdeModulePkg/Ata: Clear PxCmd.SUD bit when the port has no device presented at AHCI mode.
MdeModulePkg/Ata: Clear PxCmd.SUD bit when the port has no device presented at AHCI mode.

Signed-off-by: Feng Tian <feng.tian@intel.com>
Reviewed-by: Sun Rui <rui.sun@intel.com>


git-svn-id: 5648d1bec6962b0a6d1d1b40eba8cf5cdb62da3d@13370 6f19259b-4bc3-4df7-8a09-765794883524

MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2,MattDevo/edk2