HID: Implement horizontal wheel handling for A4 Tech X5-005D

This mouse distinguishes horizontal wheel from vertical by a special "pseudo
event" GenericDesktop.00b8, with values of 0 for vertical and 8 for horizontal
wheel. Because this event is supplied by the parser too late, we need to delay
a wheel event, wait for this one and send either REL_WHEEL or REL_HWHEEL to
input depending on the event value.

Signed-off-by: Pavel Troller <patrol@sinus.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>