drivers: spi: spi_ll_stm32: Fix the master mode not work.
drivers: spi: spi_ll_stm32: Fix the master mode not work.

On the STM32MP1 and STM32H7 Series SoC, if slave select pin control by
software on master mode operation, the SS input/output polarity (SSIOP)
should be set to high level avoid the mode fault (MODF) error.

Signed-off-by: Harry Jiang <a1e6d6ba26573750a2729392953c48a3849ce8d5@gmail.com>

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