module: allow ndiswrapper to use GPL-only symbols

A change after 2.6.24 broke ndiswrapper by accidentally removing its
access to GPL-only symbols.  Revert that change and add comments about
the reasons why ndiswrapper and driverloader are treated in a special
way.

Signed-off-by: Pavel Roskin <proski@gnu.org>
Acked-by: Greg KH <gregkh@suse.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jon Masters <jonathan@jonmasters.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>