spi/qspi: Add compatible string for am4372.

Add a compatible string for am4372.
Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

Documentation/devicetree/bindings/spi/ti_qspi.txt

 TI QSPI controller.
 
 Required properties:
-- compatible : should be "ti,dra7xxx-qspi".
+- compatible : should be "ti,dra7xxx-qspi" or "ti,am4372-qspi".
 - reg: Should contain QSPI registers location and length.
 - #address-cells, #size-cells : Must be present if the device has sub-nodes
 - ti,hwmods: Name of the hwmod associated to the QSPI

drivers/spi/spi-ti-qspi.c

@@ -453,6 +453,7 @@ static int ti_qspi_runtime_resume(struct device *dev)
 
 static const struct of_device_id ti_qspi_match[] = {
 	{.compatible = "ti,dra7xxx-qspi" },
+	{.compatible = "ti,am4372-qspi" },
 	{},
 };
 MODULE_DEVICE_TABLE(of, ti_qspi_match);