Update _reset for MCP2221

[caternuson]

For #7.

Basically just adding exception type that gets thrown for MCP2221 case.

(blinka) hellokitty@bench:~/repos/Adafruit_CircuitPython_SGP40$ python3
Python 3.8.10 (default, Jun  2 2021, 10:49:15) 
[GCC 9.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import board
>>> import adafruit_sgp40
>>> sgp = adafruit_sgp40.SGP40(board.I2C())
>>> sgp.raw
2
>>> sgp.raw
24895
>>> sgp.raw
25563
>>> 

[caternuson]

@ladyada just had another idea - could also change exception thrown by MCP2221 to match CP?

So change this:
https://github.com/adafruit/Adafruit_Blinka/blob/4f4e6af0a2c2912d7662f0160849806507b125bd/src/adafruit_blinka/microcontroller/mcp2221/mcp2221.py#L233
to be an OSError to match here:
https://github.com/adafruit/circuitpython/blob/b36187102f17ab9031eeb9fb724c82b93d13ef42/shared-bindings/busio/I2C.c#L261

[ladyada]

yah its a good idea to change the exception (also)!