rtc: add xilinx zynqmp rtc driver

Add support for RTC controller found on Xilinx Zynq Ultrascale+ MPSoC
platform.

Signed-off-by: Suneel Garapati <suneel.garapati@xilinx.com>
Acked-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 0f65a22..9d42906 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1116,6 +1116,13 @@
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-opal.
 
+config RTC_DRV_ZYNQMP
+	tristate "Xilinx Zynq Ultrascale+ MPSoC RTC"
+	depends on OF
+	help
+	  If you say yes here you get support for the RTC controller found on
+	  Xilinx Zynq Ultrascale+ MPSoC.
+
 comment "on-CPU RTC drivers"
 
 config RTC_DRV_DAVINCI