selftest/tls: Add test to verify received 'type' of non-data record

Test case 'control_msg' has been updated to peek non-data record and
then verify the type of record received. Subsequently, the same record
is retrieved without MSG_PEEK flag in recvmsg().

Signed-off-by: Vakul Garg <vakul.garg@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>