dt-bindings: Add devicetree bindings

Add snapshot of device tree bindings from keystone common kernel, branch
"android-mainline-keystone-qcom-release" at c4c12103f9c0 ("Snap for 9228065
from e32903b9a63bb558df8b803b076619c53c16baad to
android-mainline-keystone-qcom-release").

Change-Id: I7682079615cbd9f29340a5c1f2a1d84ec441a1f1
Signed-off-by: Melody Olvera <quic_molvera@quicinc.com>

bindings/spi/sqi-pic32.txt

@@ -0,0 +1,18 @@
+Microchip PIC32 Quad SPI controller
+-----------------------------------
+Required properties:
+- compatible: Should be "microchip,pic32mzda-sqi".
+- reg: Address and length of SQI controller register space.
+- interrupts: Should contain SQI interrupt.
+- clocks: Should contain phandle of two clocks in sequence, one that drives
+          clock on SPI bus and other that drives SQI controller.
+- clock-names: Should be "spi_ck" and "reg_ck" in order.
+
+Example:
+	sqi1: spi@1f8e2000 {
+		compatible = "microchip,pic32mzda-sqi";
+		reg = <0x1f8e2000 0x200>;
+		clocks = <&rootclk REF2CLK>, <&rootclk PB5CLK>;
+		clock-names = "spi_ck", "reg_ck";
+		interrupts = <169 IRQ_TYPE_LEVEL_HIGH>;
+	};