ARM: pm: hide 1st and 2nd arguments to cpu_suspend from platform code

The first and second arguments shouldn't concern platform code, so
hide them from each platforms caller.

Tested-by: Kevin Hilman <khilman@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>