rtc: sirfsoc: remove .remove

dpm_sysfs_remove() and device_pm_remove() are already called by
device_del() on device removal so there is no need to call
device_init_wakeup(dev, false) from the driver and it allows to remove the
.remove callback.

Link: https://lore.kernel.org/r/20191021155806.3625-3-alexandre.belloni@bootlin.com


Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>