we save the l2x0 registers at the first initialization, and platform codes
can get them to restore l2x0 status after wakeup.

Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Reviewed-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>