device/pine64-pinephone: fix pogopin i2c bus

The i2c bus for the pogo pins was locked up because the level shifter is powered by the regulator used for the cameras. This enables that specific regular for the gpios the i2c bus is on so the pull-ups work when reading and writing from the pogo pins.

can be tested by running i2cdetect -y 3 and seeing it returns instantly

Fixes #966 (closed)