drivers : timer : Add MEC1501 32KHz kernel timer driver

Add a kernel timer driver for the MEC1501 32KHz RTOS timer.
This timer is a count down 32-bit counter clocked at a fixed
32768 Hz. It features one-shot, auto-reload, and halt count down
while the Cortex-M is halted by JTAG/SWD. This driver is based
on the new Intel local APIC driver. The driver was tuned for
accuracy at small sleep values. Added a work-around for RTOS
timer restart issue. RTOS timer driver requires board ticks per
second to be 32768 if tickless operation is configured.

Signed-off-by: Scott Worley <scott.worley@microchip.com>