fix silab compile issues

Author: dhalbert

ports/silabs/common-hal/_bleio/PacketBuffer.c

@@ -145,7 +145,7 @@ void _common_hal_bleio_packet_buffer_construct(
     uint32_t *outgoing_buffer1,
     uint32_t *outgoing_buffer2,
     size_t max_packet_size,
-    ble_event_handler_t static_handler_entry) {
+    ble_event_handler_t *static_handler_entry) {
 
     bleio_characteristic_properties_t temp_prop;
     self->characteristic = characteristic;

ports/silabs/common-hal/microcontroller/__init__.c

@@ -60,6 +60,9 @@ void common_hal_mcu_on_next_reset(mcu_runmode_t runmode) {
     }
 }
 
+// CHIP_Reset does not return, but is not declared as such in the SDK.
+void __attribute__ ((noreturn)) CHIP_Reset(void);
+
 void common_hal_mcu_reset(void) {
     filesystem_flush(); // TODO: implement as part of flash improvements
     CHIP_Reset();