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/Makefile b/tools/binman/test/Makefile
index 786d1b0..217d13c 100644
--- a/tools/binman/test/Makefile
+++ b/tools/binman/test/Makefile
@@ -11,7 +11,7 @@
 
 LDS_UCODE := -T u_boot_ucode_ptr.lds
 
-TARGETS = u_boot_ucode_ptr u_boot_no_ucode_ptr
+TARGETS = u_boot_ucode_ptr u_boot_no_ucode_ptr bss_data
 
 all: $(TARGETS)
 
@@ -21,6 +21,9 @@
 u_boot_ucode_ptr: CFLAGS += $(LDS_UCODE)
 u_boot_ucode_ptr: u_boot_ucode_ptr.c
 
+bss_data: CFLAGS += bss_data.lds
+bss_data: bss_data.c
+
 clean:
 	rm -f $(TARGETS)