Fix bug in build.sh on wp76xx, remove all build artifacts, refactor Makefile some for wifi, and make board names lower-case

green_* targets were broken by commit 7ec4d513.

Remove gpsSensor app from the default mangOH.sdef because it creates a
lot of noise in the logs when it's not able to get a GPS fix. Also, the
location values it produces are intentionally slightly wrong to simulate
movement. This may confuse users who would expect the GPS location to be
accurate.

The code is functionally identical to what it was before, but the
dhub_integration branch has been merged with master now.

This commit overwrites the previous backporting that was done in order
to introduce the backporting work as a separate commit to simplify
future maintenance.

The updated driver will support oversampling ratio properly if the
kernel is new enough to contain the required IIO feature.

 - Remove trailing whitespace
 - Remove #if 1 ... #endif

Fix a bug where the battery charger i2c_client variable was
overwritten while mapping the battery gauge in the mangOH yellow module.

This is a re-implementation of work done in 497117a7 which was
overwritten by merge commit 03608c12.

Reduce repetition by passing offsets rather than absolute GPIO numbers
to the gpio_initial_status and gpio_final_status functions.

Use devm_gpio_request_one instead of devm_gpio_request + gpio_direction_output

These apps may be added back into the SDEF once they are published.
apps/mangOHRedSensorToCloud/redSensor
apps/mangOHRedSensorToCloud/redCloud