WIP: SMC power
This adds regulator control to imx serial driver.
This works but I it's not the correct way to solve this
- Adds a second user of the gnss regulator so that regulator never turns off
- The regulator isn't turned on and off when the port is opened and closed
We either need to keep abusing the LED interface for now or expand/abuse the gnss driver framework
Anyone else have a better idea ?