pwm: tiehrpwm: Handle deferred probe with dev_err_probe()

pwm: tiehrpwm: Handle deferred probe with dev_err_probe()

The devm_clk_get() may return -EPROBE_DEFER which is not handled properly
by TI EHRPWM driver and causes unnecessary boot log messages.

Hence, add proper deferred probe handling with new dev_err_probe() API.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>