drivers: pwm: introduce PWM driver for NXP S32 EMIOS

This introduces PWM driver with supporting PWM output
APIs based on NXP S32 EMIOS peripheral. This supports
three mode: OPWFMB, OPWMCB and OPWMB.

OPWFMB uses internal counter, the new period and duty
cycle takes effect immediately.

OPWMCB and OPWMB use external counter as timebase, changing
PWM period at runtime will impact to all channels share the
same timebase. Also the new period and duty cycle take effect
in next period boundary of the timebase

Signed-off-by: Dat Nguyen Duy <dat.nguyenduy@nxp.com>