Input: ab8500-ponkey - Fix module autoload for OF platform driver

This platform driver has a OF device ID table but the OF module
alias information is not created so module autoloading won't work.

Signed-off-by: Luis de Bethencourt <luis@debethencourt.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>