The kernel version required to run tests is v4.16 while README says
it's v4.11. Fix it.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
A comprehensive testing framework is included with the library and can be
used to test both the library code and the linux kernel user-space interface.
-The minimum kernel version required to run the tests is 4.11. The tests work
+The minimum kernel version required to run the tests is 4.16. The tests work
together with the gpio-mockup kernel module which must be enabled. NOTE: the
module must not be built-in.