minor twl4030-core cleanups

Minor twl4030-core cleanups:  alphabetize the creation of the
new sub-function nodes; wrap an #if around the OMAP-only part
(to get more general build testing when this goes upstream);
remove reference to undocumented "twl3040" variant.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Moved gpio before keypad driver due to alphabetic order.

Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>