fpga: e31x/e320/n3xx/x400: Rework device tree file generation

... to support custom image core name, example:

    rfnoc_image_builder -y n310_rfnoc_image_core.yml -n my_custom_name

The device tree source files were renamed to match the target
name used in the Makefile.

    example:
        old: dts/usrp_n310_fpga_hg.dts
        new: dts/N310_HG.dts

The source file is used to compile the final .dts file in the BUILD_DIR.

    example: build-my_custom_name/N310_HG.dts

The final .dts file is copied to the BUILD_OUTPUT_DIR as part of the
post build steps and renamed to the custom image core name.

    example: build/my_custom_name.dts

This completes the change that was introduced with commit 2afc66f132.


Original-commit: d40db57f2e03c322ac6b0001e0a59d4a14a5a3b9

top/n3xx/dts/N320_AA.dts

@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0 OR X11
+/*
+ * Copyright (c) 2017 National Instruments Corp
+ */
+
+/dts-v1/;
+/plugin/;
+
+#include "n320-fpga.dtsi"
+
+&fpga_full {
+	uio@40004000 {
+		compatible = "usrp-uio";
+		reg = <0x40004000 0x1000>;
+		reg-names = "misc-auro-regs0";
+		status = "okay";
+	};
+
+
+	uio@4000c000 {
+		compatible = "usrp-uio";
+		reg = <0x4000c000 0x1000>;
+		reg-names = "misc-auro-regs1";
+		status = "okay";
+	};
+};
+
+#include "n320-common.dtsi"
+#include "dma-common.dtsi"