Port Radio to RTOS

[kylestach]

We need to port the radio to RTOS so we can take advantage of yielding (instead of just delaying for 1ms).

This should basically look like the following:

static SemaphoreHandle_t radio_semaphore;

void radio_interrupt() {
    xSemaphoreGiveFromISR(radio_semaphore, NULL);
}

void radio_task_function() {
    while (true) {
        // TODO: Request data from the ISM
        if (xSemaphoreTake(radio_semaphore, 1ms_in_ticks)) {
            // TODO: Get data from the ISM
        }
    }
}