rtc: Remove ARCH_KIRKWOOD dependency

mach-kirkwood has been removed, now that kirkwood lives in mach-mvebu.
ARCH_MVEBU is sufficient.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: rtc-linux@googlegroups.com
Link: https://lkml.kernel.org/r/1409417172-6846-6-git-send-email-andrew@lunn.chSigned-off-by: Jason Cooper <jason@lakedaemon.net>

drivers/rtc/Kconfig

@@ -1198,7 +1198,7 @@ config RTC_DRV_TX4939
 
 config RTC_DRV_MV
 	tristate "Marvell SoC RTC"
-	depends on ARCH_KIRKWOOD || ARCH_DOVE || ARCH_MVEBU
+	depends on ARCH_DOVE || ARCH_MVEBU
 	help
 	  If you say yes here you will get support for the in-chip RTC
 	  that can be found in some of Marvell's SoC devices, such as