Rework build: Windows dependency building fix

One variable misssing

Fixes #8060

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8061)

Configurations/windows-makefile.tmpl

@@ -613,6 +613,7 @@ $res: $deps
 EOF
      }
      my $obj = platform->obj($args{obj});
+     my $dep = platform->dep($args{obj});
      if ($srcs[0] =~ /\.asm$/) {
          return <<"EOF";
 $obj: $deps