power: pmic: pca9450: Add support for system reset

power: pmic: pca9450: Add support for system reset

The family of PCA9450 PMICs have the ability to perform system resets.
Restarting via PMIC is preferred method of restarting the system as all
the peripherals are brought to a know state after a power-cycle. The
PCA9450 features a cold restart procedure which is initiated by an I2C
command 0x14 to the SW_RST register.

Support in Linux for restarting via PCA9450 PMIC has been added by
Linux commit 6157e62b07d9 ("regulator: pca9450: Add restart handler").

Now add support for it also in the U-Boot via sysreset framework.

Signed-off-by: Primoz Fiser <primoz.fiser@norik.com>
Reviewed-by: Paul Geurts <paul.geurts@prodrive-technologies.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>