Patch from Ben Dooks

Fix the idle code on the s3c2412 as the default
code is using bits in the CLKCON register that are
no-longer there.

Provide an override for the idle code, and ensure
that the power configuration is set to allow idle
instead of stop or sleep.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>