rtc: add driver for MXC's internal RTC module

This adds a driver for Freescale's MXC internal real time clock modules.

The code is taken from Freescale's BSPs, but modified to fit the current
kernel coding mechanisms.  Also, the PMIC external clock function was
removed for now to not add dead bits and keep the code as simple as
possible.

[akpm@linux-foundation.org: make PIE_BIT_DEF[] static]
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>

Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Daniel Mack <daniel@caiaq.de>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/Kconfig

@@ -509,6 +509,17 @@ config RTC_DRV_M48T59
 	  This driver can also be built as a module, if so, the module
 	  will be called "rtc-m48t59".
 
+config RTC_MXC
+	tristate "Freescale MXC Real Time Clock"
+	depends on ARCH_MXC
+	depends on RTC_CLASS
+	help
+	   If you say yes here you get support for the Freescale MXC
+	   RTC module.
+
+	   This driver can also be built as a module, if so, the module
+	   will be called "rtc-mxc".
+
 config RTC_DRV_BQ4802
 	tristate "TI BQ4802"
 	help

drivers/rtc/Makefile

@@ -46,6 +46,7 @@ obj-$(CONFIG_RTC_DRV_M41T94)	+= rtc-m41t94.o
 obj-$(CONFIG_RTC_DRV_M48T35)	+= rtc-m48t35.o
 obj-$(CONFIG_RTC_DRV_M48T59)	+= rtc-m48t59.o
 obj-$(CONFIG_RTC_DRV_M48T86)	+= rtc-m48t86.o
+obj-$(CONFIG_RTC_MXC)		+= rtc-mxc.o
 obj-$(CONFIG_RTC_DRV_BQ4802)	+= rtc-bq4802.o
 obj-$(CONFIG_RTC_DRV_SUN4V)	+= rtc-sun4v.o
 obj-$(CONFIG_RTC_DRV_STARFIRE)	+= rtc-starfire.o