mgmt/osdp: phy: Catch out-of-order SC packets and fail

During handshake, only certain types of secure block types (<= SCS_14)
are allowed. A rouge CP/PD can try to bypass the handshake by directly
sending a secure block type ahead of the sequence and gain a secure
channel. Fix this by adding a check in packet decode time.

Signed-off-by: Siddharth Chandrasekaran <sidcha.dev@gmail.com>