[SPARC64]: Kconfig fix (GEN_RTC dependencies)

Yet another architecture not coverd by GEN_RTC - sparc64 never picked
it until now and it doesn't have asm/rtc.h to go with it, so it
wouldn't compile anyway (or have these ioctls in the user-visible
headers, for that matter).

FWIW, I'm very tempted to introduce ARCH_HAS_GEN_RTC and have it set
in arch/*/Kconfig for architectures that know what to do with this
stuff - for something supposedly generic the list of architectures
where it doesn't work is getting too long...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/char/Kconfig

@@ -735,7 +735,7 @@ config SGI_IP27_RTC
 
 config GEN_RTC
 	tristate "Generic /dev/rtc emulation"
-	depends on RTC!=y && !IA64 && !ARM && !PPC64 && !M32R && !SPARC32
+	depends on RTC!=y && !IA64 && !ARM && !PPC64 && !M32R && !SPARC32 && !SPARC64
 	---help---
 	  If you say Y here and create a character special file /dev/rtc with
 	  major number 10 and minor number 135 using mknod ("man mknod"), you