[AXPxxx] Add support for AXP2101 and AXP202

[TD-er]

Split the code into several sections for AXP192/AXP2101/AXP202

ToDo:

• Test AXP192 on real hardware
• Test AXP2101 on real hardware
• Test AXP202 on real hardware
• Add more defines/boards using these chips
• Add defines on which LDO/DC ports should be enabled/disabled to be used in board .h files.

The code for AXP192 should not have changed, so that should probably be safe to use.

!!!The other chips have absolutely NOT been tested on real hardware!!!

Status: "it compiles"

Do NOT run this on real hardware unless you really know what to check for your board!

Fixes: #990

[TD-er]

@cyberman54
Please note the state of this code is "it compiles".
So please have a very thorough look before uploading it to some board as I really hope I did not mess up.

[cyberman54]

Thanks for this work. Merged to new temporary development branch "feature-axp2101". Using for testing.

[TD-er]

Will you continue from here?
Or should I try to tweak some more? (from that branch)

[cyberman54]

please use the feature-axp2102 branch, i will continue and test from here. First, will merge the experimental tsupremes3.hal from development branch with your axp20xx.hal, then check voltages for T-Supreme, and then give it a try.

[TD-er]

Please double/triple check to see if I do toggle the correct DCDC/LDO channels

[cyberman54]

Please double/triple check to see if I do toggle the correct DCDC/LDO channels

@TD-er Meanwhile, i found some prior art here:
https://github.com/meshtastic/firmware/blob/master/src/Power.cpp#L843

This should work, because the purchased T-Beam Supreme S3 came with working Meshtastic firmware preinstalled.