[PATCH] rtc: Make rtc-rs5c348 driver hotplug-aware

The rtc-rs5c348 SPI driver name doesn't match its module name, which
prevents it from properly hotplugging.  There is only one in-tree user
of its driver, which is fixed by this patch too.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: David Brownell <david-b@pacbell.net>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>