Both functions accept a series of event types/codes tuples, terminated by -1.
For the even type INPUT_PROP_MAX (an invalid type otherwise) the code is used
as a property to enable.

The _abs function als takes an array of absinfo, with absinfo.value
determining the axis to change. If none are given, abs axes are initialized
with default settings.

Both functions abort on failure, so the caller does not need to check the
return value.

Example code for creating a rel device:

struct libevdev_uinput *uinput;
struct input_id id = { ... };
uinput = litest_create_uinput_device("foo", &id,
                                     EV_REL, REL_X,
                                     EV_REL, REL_Y,
                                     EV_KEY, BTN_LEFT,
                                     INPUT_PROP_MAX, INPUT_PROP_BUTTONPAD,
                                     -1);
libevdev_uinput_write_event(uinput, EV_REL, REL_X, -1);
libevdev_uinput_write_event(uinput, EV_SYN, SYN_REPORT, 0);
...
libevdev_uinput_destroy(uinput);

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>