pwm: microchip-core: Drop driver local locking

The pwm core already serializes .apply() and .get_state(), so the driver
local lock is always free and adds no protection.

Drop it.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/6d6ef0376ea0058b040eec3b257e324493a083f1.1750788649.git.u.kleine-koenig@baylibre.com


Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>