selftests: livepatch: add missing fragments to config

When generating config with 'make defconfig kselftest-merge' fragment
CONFIG_TEST_LIVEPATCH=m isn't set.

Rework to enable CONFIG_LIVEPATCH and CONFIG_DYNAMIC_DEBUG as well.
Signed-off-by: NAnders Roxell <anders.roxell@linaro.org>
Signed-off-by: NShuah Khan <skhan@linuxfoundation.org>

tools/testing/selftests/livepatch/config

+CONFIG_LIVEPATCH=y
+CONFIG_DYNAMIC_DEBUG=y
 CONFIG_TEST_LIVEPATCH=m