Exporting the function allows us to calculate the resolution in third
party drivers like hid-multitouch.
This patch also complete the function with additional valid axes.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>