rtc: add rtc-lpc24xx driver

Add driver for the RTC found on NXP LPC178x/18xx/408x/43xx devices.
The RTC provides calendar and clock functionality together with
alarm interrupt support.

Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 533bfa3..e132ccb 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1456,6 +1456,18 @@
 	  This driver can also be buillt as a module. If so, the module
 	  will be called rtc-jz4740.
 
+config RTC_DRV_LPC24XX
+	tristate "NXP RTC for LPC178x/18xx/408x/43xx"
+	depends on ARCH_LPC18XX || COMPILE_TEST
+	depends on OF && HAS_IOMEM
+	help
+	  This enables support for the NXP RTC found which can be found on
+	  NXP LPC178x/18xx/408x/43xx devices.
+
+	  If you have one of the devices above enable this driver to use
+	  the hardware RTC. This driver can also be buillt as a module. If
+	  so, the module will be called rtc-lpc24xx.
+
 config RTC_DRV_LPC32XX
 	depends on ARCH_LPC32XX
 	tristate "NXP LPC32XX RTC"