move irqhandler to application

tud_isr() must be called by application to forward the irqhandle to the
stack

hw/bsp/seeeduino_xiao/seeeduino_xiao.c

@@ -35,6 +35,14 @@
 #include "hpl_pm_config.h"
 #include "hpl/pm/hpl_pm_base.h"
 
+//--------------------------------------------------------------------+
+// Forward USB interrupt events to TinyUSB IRQ Handler
+//--------------------------------------------------------------------+
+void USB_Handler(void)
+{
+  tud_isr(0);
+}
+
 //--------------------------------------------------------------------+
 // MACRO TYPEDEF CONSTANT ENUM DECLARATION
 //--------------------------------------------------------------------+