SAMD/L: Move content of chip/sam_memorymap.h to chip.h; move chip/sam_pinmap. to sam_pinmap.h for consistency with other header files

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.