tests: add a test case for using misc line flags together

tests: add a test case for using misc line flags together

This adds a test case that verifies that the ACTIVE_LOW flag works
correctly when used together with OPEN_SOURCE and OPEN_DRAIN flags.

Note: a bug has been discovered in the kernel that makes the LINEINFO
ioctl() incorrectly report the direction of lines requested with
open-drain or open-source flags as 'input' if the underlying hardware
doesn't support these config options. A patch fixing it has been sent
and once it's released, the FIXME's added by this patch will be
removed.

While at it: extend the previous misc flags test with additional checks
of the reported direction, but disable the one that fails due to the
bug mentioned above.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>