mgmt: ec_host_cmd: add PM for SPI STM32 backend

The SPI STM32 Host Command backend doesn't use general SPI driver, so it
has to implement Power Management on its own.

The suspend procedure includes: setting pins to the sleep state,
disabling device clock and disabling CS pin interrupt.

Signed-off-by: Dawid Niedzwiecki <dawidn@google.com>
1 file changed