soc: fsl: add GUTS driver for QorIQ platforms

The global utilities block controls power management, I/O device
enabling, power-onreset(POR) configuration monitoring, alternate
function selection for multiplexed signals,and clock control.

This patch adds a driver to manage and access global utilities block.
Initially only reading SVR and registering soc device are supported.
Other guts accesses, such as reading RCW, should eventually be moved
into this driver as well.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>