Fix i2c.setup() for pins >= 32

[tomsci]

• This PR is for the dev branch rather than for the release branch.
• This PR is compliant with the other contributing guidelines as well (if not, please describe why).
• I have thoroughly tested my contribution.
• The code changes are reflected in the documentation at docs/*.

pin_bit_mask in i2c_sw_master.c is a 64bit value and the current code shifts an int sized 1, so doesn't work for any pin numbers >= 32 because it's only shifting a 32-bit value. The upshot is software i2c doesn't work (on the default pins) on esp32s2 and later and probably some others too.

This change fixes that, by using a 64-bit 1 meaning the pin_bit_mask gets correctly set even for pin numbers above 32.

Tested on adafruit feather esp32s2 using pins 41 and 42 (Sda and Scl)

[tomsci]

Any chance you could look at this one while you're here @jmattsson? :D

[jmattsson]

Yep! Thanks for the fix!