wait after Arduino 1200 baud reset to allow chip to reboot and re-enumerate
wait after Arduino 1200 baud reset to allow chip to reboot and re-enumerate

In the latest 1.6.18 Arduino core, there's a 250ms reset delay during
which touching the serial port again will cancel the reset, so we must
wait at least that long or the bootloader reset will fail [1].

We also need to wait a bit longer for the chip to reboot and the USB
serial port to re-appear, or else bossa will fail to open it for SAM-BA.

In my testing, 500ms is too short, but 1s works consistently.

[1] https://github.com/arduino/ArduinoCore-samd/blob/1.6.18/cores/arduino/USB/CDC.cpp#L123

Signed-off-by: Allen Wild <c0235bafb4d09a895174208780decb59dc33d680@gmail.com>

shumatech/BOSSA,shumatech/BOSSA,shumatech/BOSSA