i2c_ll_stm32: Remove length < 255 restriction
i2c_ll_stm32: Remove length < 255 restriction

Allow STM32 I2C driver to handle messages with
length > 255.

Signed-off-by: Yannis Damigos <bda985a2727ac24c41652a294292988d6fc7dc73@gmail.com>

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