[Orgmode] Minor buglet in orgmode Makefile

[Robert P . Goldman]

I just pulled an update from git for the first time in a long while, and when I
tried to build org-mode, it failed with an undefined function error for the
function org-float-time in org-ascii.

It only took me a moment to find the fix --- it seems like we just need to push
org-compat up the list of lisp files ahead of org-ascii, since org-compat
provides the function definition org-ascii craves.

Cheers,
R