HID: uclogic: Modular KUnit tests should not depend on KUNIT=y

While KUnit tests that cannot be built as a loadable module must depend
on "KUNIT=y", this is not true for modular tests, where it adds an
unnecessary limitation.

Fix this by relaxing the dependency to "KUNIT".

Fixes: 08809e48 ("HID: uclogic: KUnit best practices and naming conventions")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: José Expósito <jose.exposito89@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>