Fix RPI build

Signed-off-by: HiFiPhile <admin@hifiphile.com>

hw/bsp/rp2040/family.c

@@ -290,6 +290,10 @@ void board_init_after_tusb(void) {
   // nothing to do
 }
 
+void board_reset_to_bootloader(void) {
+  // not implemented
+}
+
 //--------------------------------------------------------------------+
 // USB Interrupt Handler
 // rp2040 implementation will install appropriate handler when initializing