[ARM] 4406/1: Trivial NSLU2 / NAS-100D header & setup code cleanup

This trivial patch updates the nslu2 and nas-100d headers to
remove pointless GPIO defines, and updates nslu2-setup.c
accordingly. In addition minor style cleanups to some comments
are included.

Signed-off-by: Michael-Luke Jones <mlj28@cam.ac.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>