Keep Zephyr Device tree Linux compatible

[zephyrbot]

Reported by Erwan Gouriou:

Keep Zephyr Device tree Linux compatible, with following benefits:

*Some boards being ported today on Zephyr are already supported on Linux and have a device tree files. Having single device tree file will ease maintenance
*Single repo for Device tree files could be considered
*Ease Linux to Zephyr transition
*Benefit from existing device tree tools
*Simplify DT file handling for combined "Linux Master / Zephyr slave" platforms

This brings some constraints:
-Existing node names and properties should be reused when possible
-File naming scheme should be kept

• Move stm32 boards dts file to linux dts naming rules #3490: Move stm32 boards dts file to linux dts naming rules
• Change UART "baud-rate" property to "current-speed" #3489: Change UART "baud-rate" property to "current-speed"
• Dissociate board names from device tree file names #3488: Dissociate board names from device tree file names

(Imported from Jira ZEP-2046)

[mbolivar-nordic]

@erwango I'm looking through old issues today and I wonder if this one is still relevant.

[erwango]

@mbolivar-nordic, I don't think it is. Let's close it. Txs