ccid: Handle the TPDU-length = 4 case according to CCID spec
While ISO7816-3 forbids any TPDU shorter from 5 bytes, the CCID spec begs to differ and actually permits a host to send us 4-byte TPDUs of Form 1, giving the responsibility of adding the P3=00h octet to the CCID implementation.
Let's implement this accordingly. While at it, also reject TPDUs of lengths 1, 2 and 3 bytes - just like zero-length TPDUs.
