ARM: sa1111: fix PWM state on suspend

We should not write to the SA1111 registers after setting the SLEEP
bit.  Moreover, the manual says that the PWM registers should be
disabled before we enter sleep.  So, move the clearing of these
registers earlier in the suspend sequence.

Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>