kunit: Make default kunit_test timeout configurable via both a module parameter and...

kunit: Make default kunit_test timeout configurable via both a module parameter and a Kconfig option

To accommodate varying hardware performance and use cases,
the default kunit test case timeout (currently 300 seconds)
is now configurable. Users can adjust the timeout by
either setting the 'timeout' module parameter or the
KUNIT_DEFAULT_TIMEOUT Kconfig option to their desired
timeout in seconds.

Link: https://lore.kernel.org/r/20250626171730.1765004-1-marievic@google.com
Signed-off-by: Marie Zhussupova <marievic@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>