usb-device-cdc: Fix default timeout in CDCInterface.init().

CDCInterface.__init__() sets self._timeout = 1000, then calls
self.init(**kwargs). The init() method had timeout=None as default,
which unconditionally overwrites self._timeout with None. This causes
TypeError in read(), write(), readinto(), and ioctl() which all compare
int >= self._timeout.

Set the default timeout=1000 in init() to match the intended default,
consistent with how other parameters (baudrate, bits, etc.) have their
defaults specified directly in the init() signature.

Signed-off-by: Andrew Leech <andrew.leech@planetinnovation.com.au>

Author: pi-anl

micropython/usb/usb-device-cdc/usb/device/cdc.py

@@ -122,7 +122,7 @@ def __init__(self, **kwargs):
         self.init(**kwargs)
 
     def init(
-        self, baudrate=9600, bits=8, parity="N", stop=1, timeout=None, txbuf=256, rxbuf=256, flow=0
+        self, baudrate=9600, bits=8, parity="N", stop=1, timeout=1000, txbuf=256, rxbuf=256, flow=0
     ):
         # Configure the CDC serial port. Note that many of these settings like
         # baudrate, bits, parity, stop don't change the USB-CDC device behavior