avr32: don't offer CONFIG_GEN_RTC

This patch fixes the following compile error:

<--  snip  -->

...
  CC [M]  drivers/char/genrtc.o
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/char/genrtc.c:58:21: error: asm/rtc.h: No such file or directory
...
make[3]: *** [drivers/char/genrtc.o] Error 1

<--  snip  -->
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>

drivers/char/Kconfig

@@ -776,7 +776,7 @@ config SGI_IP27_RTC
 
 config GEN_RTC
 	tristate "Generic /dev/rtc emulation"
-	depends on RTC!=y && !IA64 && !ARM && !M32R && !MIPS && !SPARC && !FRV && !S390 && !SUPERH
+	depends on RTC!=y && !IA64 && !ARM && !M32R && !MIPS && !SPARC && !FRV && !S390 && !SUPERH && !AVR32
 	---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