doc: guides: dts: improve device section

- Move to 1st option DEVICE_DT_GET
- Make device_get_binding 2nd choice
- Extend details on differences between DEVICE_DT_GET/device_get_binding
- Extend the troubleshooting section.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
1 file changed