mp_hal_delay_ms: avoid overflow when scaling ticks

This patch casts the delay argument to mp_hal_delay_ms()
from mp_uint_t to uint64_t when scaling from milliseconds
to ticks to avoid 32-bit integer overflow when time.sleep()
is called with a duration of greater than 70 minutes.

Signed-off-by: Trammell Hudson <hudson@trmm.net>

supervisor/shared/tick.c

@@ -127,12 +127,12 @@ void PLACE_IN_ITCM(supervisor_run_background_tasks_if_tick)() {
     background_callback_run_all();
 }
 
-void mp_hal_delay_ms(mp_uint_t delay) {
+void mp_hal_delay_ms(mp_uint_t delay_ms) {
     uint64_t start_tick = port_get_raw_ticks(NULL);
     // Adjust the delay to ticks vs ms.
-    delay = delay * 1024 / 1000;
-    uint64_t end_tick = start_tick + delay;
-    int64_t remaining = delay;
+    uint64_t delay_ticks = (delay_ms * (uint64_t)1024) / 1000;
+    uint64_t end_tick = start_tick + delay_ticks;
+    int64_t remaining = delay_ticks;
 
     // Loop until we've waited long enough or we've been CTRL-Ced by autoreload
     // or the user.