rtc: add mxc driver for i.MX53 SRTC

Neither rtc-imxdi, rtc-mxc nor rtc-snvs are compatible with i.MX53.

This is driver enables support for the low power domain SRTC features:
- 32-bit MSB of non-rollover time counter
- 32-bit alarm register

Select the new config option RTC_DRV_MXC_V2 to build this driver

Based on:
http://git.freescale.com/git/cgit.cgi/imx/linux-2.6-imx.git/tree/drivers/rtc/rtc-mxc_v2.c?h=imx_2.6.35_11.09.01Signed-off-by: Patrick Bruenn <p.bruenn@beckhoff.com>
Acked-by: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

drivers/rtc/Kconfig

@@ -1699,6 +1699,16 @@ config RTC_DRV_MXC
 	   This driver can also be built as a module, if so, the module
 	   will be called "rtc-mxc".
 
+config RTC_DRV_MXC_V2
+	tristate "Freescale MXC Real Time Clock for i.MX53"
+	depends on ARCH_MXC
+	help
+	   If you say yes here you get support for the Freescale MXC
+	   SRTC module in i.MX53 processor.
+
+	   This driver can also be built as a module, if so, the module
+	   will be called "rtc-mxc_v2".
+
 config RTC_DRV_SNVS
 	tristate "Freescale SNVS RTC support"
 	select REGMAP_MMIO

drivers/rtc/Makefile

@@ -107,6 +107,7 @@ obj-$(CONFIG_RTC_DRV_MT6397)	+= rtc-mt6397.o
 obj-$(CONFIG_RTC_DRV_MT7622)	+= rtc-mt7622.o
 obj-$(CONFIG_RTC_DRV_MV)	+= rtc-mv.o
 obj-$(CONFIG_RTC_DRV_MXC)	+= rtc-mxc.o
+obj-$(CONFIG_RTC_DRV_MXC_V2)	+= rtc-mxc_v2.o
 obj-$(CONFIG_RTC_DRV_NUC900)	+= rtc-nuc900.o
 obj-$(CONFIG_RTC_DRV_OMAP)	+= rtc-omap.o
 obj-$(CONFIG_RTC_DRV_OPAL)	+= rtc-opal.o