As done for other families, let's define the PWM channel in the PWM
pins table definition rather than driver.

The pwmout driver is very similar for each STM32 family.

The only family specific part is defined in pwmout_device.h file.
It mainly contains few specific information:
- The mapping of PWM/TIMERS to APB1 or APB2 so that we can get the clock
- The clock calculation uses the right APB clock, which was sometimes
not the case before and could have lead to errors in case dividers were
enabled on APB clock settings. This case is now covered.
- Inactivation of inverted support on feaw families

Correct the while loop limit and add a safe guard to avoid infinite loop.

In order to avoid possible multiple definitions errors, move the table
initialization to the C file instead of header file

Use the recommended style
if (condition) {
  do();
} else {
  do_else();
}

Typo with misplaced closing parenthesis leads to compilation error,
which is fixed with this patch