pwm: atmel-tcb: Unroll atmel_tcb_pwm_set_polarity() into only caller

[ Upstream commit 9a6ac822 ]

atmel_tcb_pwm_set_polarity() is only called once and effectively wraps
an assignment only. Replace the function call by the respective
assignment.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Claudiu Beznea <claudiu.beznea@tuxon.dev>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Stable-dep-of: 37f77070 ("pwm: atmel-tcb: Fix race condition and convert to guards")
Signed-off-by: Sasha Levin <sashal@kernel.org>