pwm: sophgo: add driver for Sophgo SG2042 PWM

Add a PWM driver for PWM controller in Sophgo SG2042 SoC.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
Link: https://lore.kernel.org/r/ae8ea1bf0bb0a09336cd8b7f627a994630524bba.1738737617.git.unicorn_wang@outlook.com


[ukleinek: Drop unneeded reset_control_assert() from error path]
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>