[FEATURE] PWM Pulse Counter needs board example and application

### Is your feature request related to a problem? Please describe.

STM32 supports PULSECOUNT feature, however someone who added CONFIG_PWM_PULSECOUNT support didn't include any board config or usage example.

In theory the apps/example/pwm has support to CONFIG_EXAMPLES_PWM_PULSECOUNT, but there is no board with it enable, so probably this feature never was really well tested.

### Describe the solution you'd like

Add some board profiles using the PWM PULSECOUNT.

### Describe alternatives you've considered

_No response_

### Verification

- [x] I have verified before submitting the report.