binman: Drop .note section from ELF

Recent versions of binutils add a '.note.gnu.property' into the ELF file.
This is not required and interferes with the expected output. Drop it.

Also fix testMakeElf() to use a different file for input and output.

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/binman/elf.py

@@ -221,6 +221,9 @@ SECTIONS
     .empty : {
         *(.empty)
     } :empty
+    /DISCARD/ : {
+        *(.note.gnu.property)
+    }
     .note : {
         *(.comment)
     } :note