rtc: rtc-lpc32xx: introduce RTC driver for the LPC32XX SoC

Add an RTC driver for the built-in RTC in the LPC32XX SoC.  This patch
includes updates from the initial review comments and updates from the v3
review.

Signed-off-by: Kevin Wells <wellsk40@gmail.com>
Signed-off-by: Durgesh Pattamatta <durgesh.pattamatta@nxp.com>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 2785a0f..636ba82 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -952,4 +952,13 @@
 	  This driver can also be buillt as a module. If so, the module
 	  will be called rtc-jz4740.
 
+config RTC_DRV_LPC32XX
+	depends on ARCH_LPC32XX
+	tristate "NXP LPC32XX RTC"
+	help
+	  This enables support for the NXP RTC in the LPC32XX
+
+	  This driver can also be buillt as a module. If so, the module
+	  will be called rtc-lpc32xx.
+
 endif # RTC_CLASS