staging: ccree: add clock management support

Some SoC which implement CryptoCell have a dedicated clock
tied to it, some do not. Implement clock support if exists
based on device tree data and tie power management to it.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>