char: remove obsolete ds1302 rtc driver

The m32r architecture was the only user of the old-style
rtc driver for ds1302. The architecture is getting removed
now, and we have a modern driver for the same hardware in
drivers/rtc/rtc-ds1302.c, so this one won't be missed.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>