This commit allows the PWM modules to be synchronized by an external
signal (other PWM module for example). The sync source can be selected
from configuration.
PWM module can also now generate a trigger when its timer reaches the duty
cycle. This trigger is used for the synchronization of other modules. It
can also be used for triggering ADC for example in the future.
Thanks to Rastislav Pavlanin and Jan Spurek from NXP support for
suggestion which helped to solve the inter-module PWM synchronization
task.
Signed-off-by: Michal Lenc <michallenc@seznam.cz>