HID: uclogic: Add KUnit tests for uclogic_rdesc_template_apply()

The uclogic_rdesc_template_apply() function is used by the driver to
generate HID descriptors from templates.

In order to avoid regressions in future patches, add KUnit tests to
test the function.

To run the tests:

 $ ./tools/testing/kunit/kunit.py run --kunitconfig=drivers/hid \
 	--kconfig_add CONFIG_VIRTIO_UML=y \
 	--kconfig_add CONFIG_UML_PCI_OVER_VIRTIO=y

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