Fix: #13203: USB device: wait_us instead of ThisThread::sleep_for, delay given is 5us

targets/TARGET_NXP/USBHAL_LPC17.cpp

@@ -411,7 +411,7 @@ void USBPhyHw::init(USBPhyEvents *events)
     LPC_PINCON->PINSEL4 |= 0x00040000;
 
     // Connect must be low for at least 2.5uS
-    ThisThread::sleep_for(300);
+    wait_us(5);
 
     // Disable control endpoints
     SIEsetEndpointStatus(EP0IN, SIE_SES_DA);