Add atomic flag for 16-bit ticks PIC24 (#488)
Add atomic flag for 16-bit ticks PIC24 (#488)

This change allows the PIC24 family of
16 bit processors to read the tick count
without a critical section when the tick
count is 16 bits.

Inspired from discussion - https://forums.freertos.org/t/xtaskgettickcount-with-critical-section-on-16-bit-mcu/14860/5
FreeRTOS/FreeRTOS-Kernel,FreeRTOS/FreeRTOS-Kernel