Linux Build Failure Fix
Linux Build Failure Fix

 - Fix for Linux build fail due to memory barrier api
   https://github.com/ARM-software/arm-enterprise-acs/issues/123

Signed-off-by: Rajat Goyal <2cacb4bf4bb421ec57b6a0ee283d6459f7ff7593@arm.com>

ARM-software/sbsa-acs,ARM-software/sbsa-acs