Put the device id-to-gpio mapping in a table to make it easier to add
new devices.  The list of supported devices is unchanged.
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Acked-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>