config_system: merge similar else conditions
config_system: merge similar else conditions

Change-Id: Ia5648268cdd064ce668920c6f447aab1d7af9cb5
Signed-off-by: David Kilroy <159cd46f289d7961b38b0171b53c05be4aaef0b6@arm.com>

ARM-software/bob-build,ARM-software/bob-build,ARM-software/bob-build,ARM-software/bob-build,ARM-software/bob-build