sh: dreamcast: rtc: push down rtc class ops into driver

The SH RTC support has an extra level of indirection to provide
either the old read_persistent_clock/update_persistent_clock
interface or the rtc-generic device for hctosys/systohc.

Both do the same thing for dreamcast, so we can do away with the
abstraction and simply let the RTC core code to take care of it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/sh/boards/mach-dreamcast/setup.c

@@ -30,7 +30,6 @@
 
 static void __init dreamcast_setup(char **cmdline_p)
 {
-	board_time_init = aica_time_init;
 }
 
 static struct sh_machine_vector mv_dreamcast __initmv = {