usb_cdc: Add usb_read_ep0_setup() interface function

Use new usb_read_ep0_setup() function when reading a setup packet -
this allows the low-level usb hardware code to better handle errors.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

src/lpc176x/usbserial.c

@@ -189,6 +189,12 @@ usb_read_ep0(void *data, uint_fast8_t max_len)
     return usb_read_packet(EP0OUT, data, max_len);
 }
 
+int_fast8_t
+usb_read_ep0_setup(void *data, uint_fast8_t max_len)
+{
+    return usb_read_ep0(data, max_len);
+}
+
 int_fast8_t
 usb_send_ep0(const void *data, uint_fast8_t len)
 {