spi: xilinx: Add support for xlnx,axi-quad-spi-1.00.a

The driver has been successfully tested with Xilinx's core
axi-quad-spi-1.0.0a. Documented on DS843:

https://www.xilinx.com/support/documentation/ip_documentation/axi_quad_spi/v1_00_a/ds843_axi_quad_spi.pdf

Cc: Mark Brown <broonie@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/spi/spi-xilinx.txt

@@ -2,7 +2,7 @@ Xilinx SPI controller Device Tree Bindings
 -------------------------------------------------
 
 Required properties:
-- compatible		: Should be "xlnx,xps-spi-2.00.a" or "xlnx,xps-spi-2.00.b"
+- compatible		: Should be "xlnx,xps-spi-2.00.a", "xlnx,xps-spi-2.00.b" or "xlnx,axi-quad-spi-1.00.a"
 - reg			: Physical base address and size of SPI registers map.
 - interrupts		: Property with a value describing the interrupt
 			  number.

drivers/spi/spi-xilinx.c

@@ -381,6 +381,7 @@ static int xilinx_spi_find_buffer_size(struct xilinx_spi *xspi)
 }
 
 static const struct of_device_id xilinx_spi_of_match[] = {
+	{ .compatible = "xlnx,axi-quad-spi-1.00.a", },
 	{ .compatible = "xlnx,xps-spi-2.00.a", },
 	{ .compatible = "xlnx,xps-spi-2.00.b", },
 	{}