Tests: bluetooth: tester: accomodate L2CAP connect commant to BTP change

BTP change extended L2CAP_CONNECT command by ECFC flag, which determines
which connection procedure is used (non-enhanced or ecred). Now, only
this flag determines the procedure used, not number of requested
channels.

This was affecting L2CAP/ECFC/BV-25-C

Signed-off-by: Krzysztof Kopyściński <krzysztof.kopyscinski@codecoup.pl>