soc: intel_adsp: added casting for C++ compiler in soc.h
soc: intel_adsp: added casting for C++ compiler in soc.h

Header soc.h is included during C++ source file compilation
and required adding C++ casts as implicit casting from void*
is forbidden. Fixed minor warning comparing signed with unsigned
integer.

Signed-off-by: Andrey Borisovich <673826e6c8b8a4405bf4a15a22d24872215fdf86@intel.com>

galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,galak/zephyr