It appears the Travis version of gcc-arm-none-eabi doesn't allow the %x
printf format specifier for size_t arguments, in contrast with the
version I'm running on Ubuntu 18.04 (15:6.3.1+svn253039-1build1).
Adds a target driver for Microchip SAM D51 / E5x family.
Tested on SAMD51G19A and SAMD51J19A. According to the datasheet, the
D51 / E5x family share the same core feature set, differing only in the
addition of CAN (E51) or ethernet controllers (E53/54). All members of
the family should be equivalent from a debug and programming perspective.
Uwe Bonnes
Ken Healy