MAINTAINERS: Add source tree entry for kunit

Patches for kunit are managed in kunit and kunit-fixes branches of
linux-kselftest tree before merged into the mainline.  However, the
MAINTAINERS section for kunit is not having the entries for the
branches.  Add the entries.

Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

MAINTAINERS

@@ -11311,6 +11311,8 @@ L:	linux-kselftest@vger.kernel.org
 L:	kunit-dev@googlegroups.com
 S:	Maintained
 W:	https://google.github.io/kunit-docs/third_party/kernel/docs/
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git kunit
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git kunit-fixes
 F:	Documentation/dev-tools/kunit/
 F:	include/kunit/
 F:	lib/kunit/