sparc64: Convert Mostek rtc to use generic RTC layer driver.

Based largely upon a patch by Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc64/Kconfig

@@ -20,6 +20,7 @@ config SPARC64
 	select HAVE_ARCH_TRACEHOOK
 	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select RTC_CLASS
+	select RTC_DRV_M48T59
 
 config GENERIC_TIME
 	bool

arch/sparc64/kernel/sparc64_ksyms.c

@@ -36,7 +36,6 @@
 #include <asm/elf.h>
 #include <asm/head.h>
 #include <asm/smp.h>
-#include <asm/mostek.h>
 #include <asm/ptrace.h>
 #include <asm/uaccess.h>
 #include <asm/checksum.h>
@@ -152,8 +151,6 @@ EXPORT_SYMBOL(flush_dcache_page);
 EXPORT_SYMBOL(__flush_dcache_range);
 #endif
 
-EXPORT_SYMBOL(mostek_lock);
-EXPORT_SYMBOL(mstk48t02_regs);
 #ifdef CONFIG_SUN_AUXIO
 EXPORT_SYMBOL(auxio_set_led);
 EXPORT_SYMBOL(auxio_set_lte);