pwm: Remove wrong implementation details from pwm_ops's documentation

pwm: Remove wrong implementation details from pwm_ops's documentation

When .get_state() is called is an implementation detail that
implementors and users shouldn't care about and rely on. Additionally
it's wrong, because with PWM_DEBUG enabled it is called more often.

Just drop the wrong statement.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/611ba758d7e9fb2695e96b23cb7ceeefb6ba8513.1717756902.git.u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>