rtc: add rtc-tx4939 driver

Add support for RTC in TX4939 SoC.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/Kconfig

@@ -705,4 +705,11 @@ config RTC_DRV_STARFIRE
 	  If you say Y here you will get support for the RTC found on
 	  Starfire systems.
 
+config RTC_DRV_TX4939
+	tristate "TX4939 SoC"
+	depends on SOC_TX4939
+	help
+	  Driver for the internal RTC (Realtime Clock) module found on
+	  Toshiba TX4939 SoC.
+
 endif # RTC_CLASS