xilinx: Add jedec compatible string for QSPI (Zynq/ZynqMP)

Add missing "jedec, spi-nor" compatible string for QSPI flash node.
Spi-nor framework uses this compatibility string to probe &
initialize flash. With missing compatibility string we are observing
below error:

Zynq> sf probe 0 0 0
 jedec_spi_nor spi_flash@0:0: unrecognized JEDEC id bytes:
00, 00, 00  Failed to initialize SPI flash at 0:0 (error -2)

Signed-off-by: Raju Kumar Pothuraju <raju.kumar-pothuraju@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/arm/dts/zynqmp-topic-miamimp-xilinx-xdp-v1r1.dts b/arch/arm/dts/zynqmp-topic-miamimp-xilinx-xdp-v1r1.dts
index 6ec96e0..300e2eb 100644
--- a/arch/arm/dts/zynqmp-topic-miamimp-xilinx-xdp-v1r1.dts
+++ b/arch/arm/dts/zynqmp-topic-miamimp-xilinx-xdp-v1r1.dts
@@ -58,7 +58,7 @@
 	status = "okay";
 	is-dual = <1>;
 	flash@0 {
-		compatible = "st,m25p80", "n25q256a";
+		compatible = "st,m25p80", "n25q256a", "jedec,spi-nor";
 		m25p,fast-read;
 		reg = <0x0>;
 		spi-tx-bus-width = <1>;