iso7816_fsm: Fix TPDUs wih Le == 1 (single byte reads)

If we expect only a single byte in response to the TPDU header,
the cuart driver sends us RX_SINGLE events, not RX_COMPLETE events.

Change-Id: I3f025bc88b9aacc07ae87307328cec56efbac2ab
Closes: OS#4741
1 file changed