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/Makefile b/drivers/firmware/Makefile
index 6c3e129..a0c250a 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -2,3 +2,4 @@
 obj-$(CONFIG_$(SPL_)ARM_PSCI_FW)	+= psci.o
 obj-$(CONFIG_TI_SCI_PROTOCOL)	+= ti_sci.o
 obj-$(CONFIG_SANDBOX)		+= firmware-sandbox.o
+obj-$(CONFIG_ZYNQMP_FIRMWARE)	+= firmware-zynqmp.o