STMicroelectronics STM32 Platforms System Controller

Properties:
   - compatible : should contain two values. First value must be :
                 - " st,stm32mp157-syscfg " - for stm32mp157 based SoCs,
                 second value must be always "syscon".
   - reg : offset and length of the register set.
   - clocks: phandle to the syscfg clock

 Example:
         syscfg: syscon@50020000 {
                 compatible = "st,stm32mp157-syscfg", "syscon";
                 reg = <0x50020000 0x400>;
                 clocks = <&rcc SYSCFG>;
         };

