pwm: Drop duplicate check against chip->npwm in of_pwm_xlate_with_flags()

args->args[0] is passed as parameter "index" to pwm_request_from_chip().
The latter function also checks for index >= npwm, so
of_pwm_xlate_with_flags() doesn't need to do that.

Link: https://lore.kernel.org/r/b06e445a6ed62a339add727eccb969a33d678386.1704835845.git.u.kleine-koenig@pengutronix.de


Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>