Cellular fixes

[KimBP]

Looking a bit into the new cellular stuff I realized more of the samples can't build with the different boards.
So little is needed to make it work, so worth it I think

[bjarki-andreasen]

Changes to devicetree compatibles, in this case redefining the compatible used in the cellular driver, which results in the driver not building at all for any board (more specifically not creating any struct devices when built), is a no from me :)

[rerickson1]

For pinnacle_100_dvk and mg100 to work with the cellular modem sample, board overlays are needed in the sample.

[KimBP]

Yes - I guess you are right. My misunderstanding.
This was purely based on my build result. Unfortunately my only modem is on a (yet) unsupported board, so haven't had a change to verify it.

Wander how sample_cellular_modem has been tested. My guess is that it has been tested only on a quectel bg95 which is referred as a quectel,bg95 in modem_cellular and as quectel,bg9x in the quectel driver.
That's a problem we need to solve.

For now I'll retract this PR

[KimBP]

For pinnacle_100_dvk and mg100 to work with the cellular modem sample, board overlays are needed in the sample.

That's one way to solve the lack of the modem alias. Still though you'll get a linker conflict with multiple definitions of __devices_dts_ord_xx (defined in both modem_cellular.c.obj and the hl8700 driver)

[rerickson1]

For pinnacle_100_dvk and mg100 to work with the cellular modem sample, board overlays are needed in the sample.

That's one way to solve the lack of the modem alias. Still though you'll get a linker conflict with multiple definitions of __devices_dts_ord_xx (defined in both modem_cellular.c.obj and the hl8700 driver)

You need a kconfig overlay to disable the HL7800 driver.