MIPS: generic: Add support for MIPSfpga

Add support for the MIPSfpga platform to generic kernel.

Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15846/
[jhogan@kernel.org: Use separate board-xilfpga.its.S. Add 32r2 and
 little endian requires to board-xilfpga.config]
Signed-off-by: James Hogan <jhogan@kernel.org>

arch/mips/boot/dts/xilfpga/nexys4ddr.dts

@@ -5,6 +5,14 @@
 / {
 	compatible = "digilent,nexys4ddr";
 
+	aliases {
+		serial0 = &axi_uart16550;
+	};
+	chosen {
+		bootargs = "console=ttyS0,115200";
+		stdout-path = "serial0:115200n8";
+	};
+
 	memory {
 		device_type = "memory";
 		reg = <0x0 0x08000000>;