rtc: zynqmp: Add support for ZynqMP RTC

The whole driver logic is taken from Linux kernel but only set/get/reset
functions are implemented. When device is power off RTC is power out of
battery.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index cbdfddb..b6692e6 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -195,4 +195,11 @@
 	  Say "yes" here to support the on chip real time clock
 	  present on TI OMAP1, AM33xx, DA8xx/OMAP-L13x, AM43xx and DRA7xx.
 
+config RTC_ZYNQMP
+	bool "Enable ZynqMP RTC driver"
+	depends on ARCH_ZYNQMP
+	help
+	  Say "yes" here to support the on chip real time clock
+	  present on Xilinx ZynqMP SoC.
+
 endmenu