PM / crypto / ux500: Use struct dev_pm_ops for power management

Make the ux500 crypto driver define its PM callbacks through
struct dev_pm_ops objects rather than by using legacy PM hooks
in struct platform_driver.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Linus Walleij <linus.walleij@linaro.org>