ARM: 7009/1: l2x0: Add OF based initialization

This adds probing for ARM L2x0 cache controllers via device tree. Support
includes the L210, L220, and PL310 controllers. The binding allows setting
up cache RAM latencies and filter addresses (PL310 only).

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>