ARM: dts: DRA7: add entry for qspi mmap region

Add qspi memory mapped region entries for DRA7xx based SoCs. Also,
update the binding documents for the controller to document this change.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>

Documentation/devicetree/bindings/spi/ti_qspi.txt

@@ -15,6 +15,10 @@ Recommended properties:
 - spi-max-frequency: Definition as per
                      Documentation/devicetree/bindings/spi/spi-bus.txt
 
+Optional properties:
+- syscon-chipselects: Handle to system control region contains QSPI
+		      chipselect register and offset of that register.
+
 Example:
 
 qspi: qspi@4b300000 {
@@ -26,3 +30,16 @@ qspi: qspi@4b300000 {
 	spi-max-frequency = <25000000>;
 	ti,hwmods = "qspi";
 };
+
+For dra7xx:
+qspi: qspi@4b300000 {
+	compatible = "ti,dra7xxx-qspi";
+	reg = <0x4b300000 0x100>,
+	      <0x5c000000 0x4000000>,
+	reg-names = "qspi_base", "qspi_mmap";
+	syscon-chipselects = <&scm_conf 0x558>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+	spi-max-frequency = <48000000>;
+	ti,hwmods = "qspi";
+};

arch/arm/boot/dts/dra7.dtsi

@@ -1154,8 +1154,10 @@ mcspi4: spi@480ba000 {
 
 		qspi: qspi@4b300000 {
 			compatible = "ti,dra7xxx-qspi";
-			reg = <0x4b300000 0x100>;
-			reg-names = "qspi_base";
+			reg = <0x4b300000 0x100>,
+			      <0x5c000000 0x4000000>;
+			reg-names = "qspi_base", "qspi_mmap";
+			syscon-chipselects = <&scm_conf 0x558>;
 			#address-cells = <1>;
 			#size-cells = <0>;
 			ti,hwmods = "qspi";