Update Ticker wrapper to handle early interrupts

Update the LowPowerTickerWrapper class to handle rather than ignore
early low power ticker interrupts. This ensures that devices don't get
stuck in sleep due to a ignored early low power ticker interrupt.

Author: c1728p9

hal/LowPowerTickerWrapper.cpp

@@ -33,7 +33,12 @@ void LowPowerTickerWrapper::irq_handler(ticker_irq_handler_type handler)
 {
     core_util_critical_section_enter();
 
-    if (_pending_fire_now || _match_check(_intf->read()) || _suspended) {
+    // This code no longer filters out early interrupts. Instead it
+    // passes them through to the next layer and ignores further interrupts
+    // until the next call to set_interrrupt or fire_interrupt (when not suspended).
+    // This is to ensure that the device doesn't get stuck in sleep due to an
+    // early low power ticker interrupt that was ignored.
+    if (_pending_fire_now || _pending_match || _suspended) {
         _timeout.detach();
         _pending_timeout = false;
         _pending_match = false;