mach-stm32: add multifunction timer driver support

mach-stm32: add multifunction timer driver support

Add support for STM32MP timer multi-function driver.
These timers can be use as counter, trigger or pwm generator.
This driver will be used to manage the main resources of the timer to
provide them to the functionnalities which need these ones.

Signed-off-by: Cheick Traore <cheick.traore@foss.st.com>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>