Add Micorchip MEC17xx family files for
hardware timers, keyboard scan, host
port 80h, UART, and watch dog timer.
BRANCH=none
BUG=
TEST=Review only.
Change-Id: Iac8a912af4d29521964f606637041b06fa7238ee
Signed-off-by: Scott Worley <scott.worley@microchip.corp-partner.google.com>