pwm: spear: Free resources only after pwmchip_remove()

Before pwmchip_remove() returns the PWM is expected to be functional. So
remove the pwmchip before disabling the clocks. The check for
pwmchip_remove()'s return value is dropped as this function returns
effectively always 0 and returning an error in a remove callback is
useless anyhow (as the device core ignores it and drops devm allocated
resources).

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>