binman: Add test for u-boot-spl-bss-pad

Add a test that we can pad the BSS with zero bytes.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/test/47_spl_bss_pad.dts b/tools/binman/test/47_spl_bss_pad.dts
new file mode 100644
index 0000000..6bd88b8
--- /dev/null
+++ b/tools/binman/test/47_spl_bss_pad.dts
@@ -0,0 +1,17 @@
+/dts-v1/;
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	binman {
+		u-boot-spl {
+		};
+
+		u-boot-spl-bss-pad {
+		};
+
+		u-boot {
+		};
+	};
+};