SAMA5 OHCI: Fix errors introduced with blind changes to match changes to LPC17 OHCI.  Fix some handling for the case where we get a falso alarm transfer completion after disconnection/cancellation

Rename SAMD directories and configuration variables to SAMDL so that the same build environment can support the SAML

SAMV7 TWIHS:  Fix logic that performs multi-message tranfers with and without repeated starts.  This change is the final piece that was required to get the maXTouch Xplained Pro workding.

The test for data partially transferred is incorrectec: chan->xfrd != xfrlen
Should be chan->xfrd > 0

From Ronly XLN.

OHCI:  Fix length calculation in all OHCI drivers:  CBP==0 means that the entire buffer was transferred, not that a null packet was tranaferred