pwm: Check actual period and duty_cycle for ignored polarity test

pwm: Check actual period and duty_cycle for ignored polarity test

When a lowlevel driver configures the wrong period that might
(historically) be ok if the emitted signal has a 100% relative duty_cycle
as that just corresponds to rounding down the duty_cycle to 0 which is an
allowed thing to do for a lowlevel driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/bc511c0250ea2f6390e4209ab1ea9c08a3c18612.1751994988.git.u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>