intel/bd82x6x: Add new current for native USB ports

Change-Id: I88ef36b94b961a318d280d8de1b8721fcbeb93b0
Signed-off-by: Damien Zammit <damien@zamaudio.com>
Reviewed-on: http://review.coreboot.org/7237
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>