ARM: 7615/1: cache-l2x0: aurora: Invalidate during clean operation with WT enable

This patch fixes a bug for Aurora L2 cache controller when the
write-through mode is enable. For the clean operation even if we don't
have to flush the lines we still need to invalidate them.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>