e1000 driver now compiles with fewer modifications

- Change some include path in the e1000 drivers
  - Add some files from the FreeBSD source tree (modification in
    freebsd-to-rtems.py)
    - Avoid inconsistent functions declarations: the bool_t and/or
    boolean_t are not the same between rtems and freebsd so that a
    function with the prototype bool_t foobar() and another boolean_t
    foobar() does not compile on rtems. (see if_igb.c for example)
      Joel Note: These are still inconsistent on the FreeBSD side and need
                 to be addressed by them. We will just make the prototype
                 match the body until they give us a solution.

freebsd/kern/init_main.c

@@ -110,9 +110,7 @@ struct	proc *initproc;
 
 int	boothowto = 0;		/* initialized so that it can be patched */
 SYSCTL_INT(_debug, OID_AUTO, boothowto, CTLFLAG_RD, &boothowto, 0, "");
-#endif
 int	bootverbose;
-#ifndef __rtems__
 SYSCTL_INT(_debug, OID_AUTO, bootverbose, CTLFLAG_RW, &bootverbose, 0, "");
 
 /*