RTC: Add JZ4740 RTC driver

Add support for the RTC unit on JZ4740 SoCs.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Paul Gortmaker <p_gortmaker@yahoo.com>
Cc: rtc-linux@googlegroups.com
Acked-by: Wan ZongShun <mcuos.com@gmail.com>
Cc: linux-mips@linux-mips.org 
Cc: linux-kernel@vger.kernel.org
Cc: Alessandro Zummo <a.zummo@towertech.it>,
Patchwork: https://patchwork.linux-mips.org/patch/1424/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 9d6952e..4301a6c 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -905,4 +905,15 @@
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-mpc5121.
 
+config RTC_DRV_JZ4740
+	tristate "Ingenic JZ4740 SoC"
+	depends on RTC_CLASS
+	depends on MACH_JZ4740
+	help
+	  If you say yes here you get support for the Ingenic JZ4740 SoC RTC
+	  controller.
+
+	  This driver can also be buillt as a module. If so, the module
+	  will be called rtc-jz4740.
+
 endif # RTC_CLASS