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

In go_os_start that sets the IDLE thread stack coloration, mov does not set condition codes which are tested by the following beq.  Need to use movs instead.  Noted by David Sidrane

 kl: enable the clocks to UART1 and UART2. The previous version would cause a hard fault on startup due to the modules not being clocked.  Also drop the GPIO configuration as it's done during kl_start().  From Michael Hope.

kl: fix PWM debugging. TPM1 and TPM2 have two channels instead of six and will hard fault if you try to read the missing channels.  From Michael Hope.

Misc improvements to the CDC/ACM host driver, mostly related to parsing the configuration descriptor.  Still does not work.