The pwm utility cant set the only flag defined (PWM_POLARITY_INVERTED) so this patch add the option -I (capital letter i) to send it to the drivers.
None of existing PWM driver have implemented support for flags. But soon:ish I will put up an review of a pwm driver using TI OMAP DMTimer.
Also fix the types of period and duty in share/man/man9/pwmbus.9 to match the one in sys/dev/pmw/pwmbus.c.