binman: ftest: Add test for xilinx-bootgen etype

Add test for the 'xilinx-bootgen' etype

Signed-off-by: Lukas Funke <lukas.funke@weidmueller.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Allow missing bootgen tool; comment testXilinxBootgenMissing() comment:
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/test/307_xilinx_bootgen_sign.dts b/tools/binman/test/307_xilinx_bootgen_sign.dts
new file mode 100644
index 0000000..02acf86
--- /dev/null
+++ b/tools/binman/test/307_xilinx_bootgen_sign.dts
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+/dts-v1/;
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	binman {
+		xilinx-bootgen {
+			auth-params = "ppk_select=0", "spk_id=0x00000000";
+			pmufw-filename = "pmu-firmware.elf";
+			psk-key-name-hint = "psk";
+			ssk-key-name-hint = "ssk";
+
+			u-boot-spl-nodtb {
+			};
+			u-boot-spl-dtb {
+			};
+		};
+	};
+};