zynqmp: firmware: Add Xilinx ZynqMP firmware driver

Add simple ZynqMP firmware drive to populate child nodes under
zynqmp_firmware DT node.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index 873bc8c..b70a206 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -26,3 +26,13 @@
 
 	  This protocol library is used by client drivers to use the features
 	  provided by the system controller.
+
+config ZYNQMP_FIRMWARE
+	bool "ZynqMP Firmware interface"
+	select FIRMWARE
+	help
+	  Firmware interface driver is used by different
+	  drivers to communicate with the firmware for
+	  various platform management services.
+	  Say yes to enable ZynqMP firmware interface driver.
+	  If in doubt, say N.