In npcx7 series, there're 8 Pulse Width Modulator (PWM) modules and each
one support generating a single 16-bit PWM output. A 16-bit clock
prescaler (PRSCn) and a 16-bit counter (CTRn) determine the cycle time,
the minimal possible pulse width, and the duty-cycle steps.
Beside introducing pwm driver for Nuvoton NPCX series, this CL also
includes:
1. Add PWM device tree declarations.
2. Zephyr PWM api implementation.
3. Add aliases in npcx7m6fb_evb board device tree file for supporting
samples/basic/blinky_pwm application and pwm test suites
Signed-off-by: Mulin Chao <MLChao@nuvoton.com>
Mulin Chao