HID: uclogic: Split pen and frame raw event handling

In order to avoid ending up with  a big uclogic_raw_event function,
split it in two smaller functions: uclogic_raw_event_pen for the pen
events and uclogic_raw_event_frame for the pad events.

Signed-off-by: Nikolai Kondrashov <spbnick@gmail.com>
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>