[efi] Ensure EFI binaries comply with Authenticode requirements

Authenticode requires that the size of the raw file must equal the
size of the OptionalHeader.SizeOfHeaders plus the sum of all sections'
SizeOfRawData.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/util/elf2efi.c

 	struct pe_section *section;
 	unsigned long fpos = 0;
 
+	/* Align length of headers */
+	fpos = pe_header->nt.OptionalHeader.SizeOfHeaders =
+		efi_file_align ( pe_header->nt.OptionalHeader.SizeOfHeaders );
+
 	/* Assign raw data pointers */
-	fpos = efi_file_align ( pe_header->nt.OptionalHeader.SizeOfHeaders );
 	for ( section = pe_sections ; section ; section = section->next ) {
 		if ( section->hdr.SizeOfRawData ) {
 			section->hdr.PointerToRawData = fpos;