HID: alps: a few cleanups

Remove an unnecessary codes.
Change input_ivent() function to appropriate function.
Add the device ID of "HID_DEVICE_ID_ALPS_U1_DUAL".

[jkosina@suse.cz: removed unnecessary bitshifts of values passed
 input_report_key() as spotted by Dmitry]
Signed-off-by: Masaki Ota <masaki.ota@jp.alps.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>