board: sensry: ganymed_bob_sy120 - doc update

[tswaehn]

In this commit we updated the document page for the sensry ganymed_bob_sy120 boards.

[tswaehn]

@maass-hamburg could you please have a look at the changes?

[tswaehn]

when using: .. zephyr:board:: in index.rst

it seems to be not possible to prepare docs for:

.. zephyr:board:: ganymed_bob

or

.. zephyr:board:: ganymed_bob/sy120_gbm

.. zephyr:board:: ganymed_bob/sy120_gen1

if there are 2 variants depending on different soc type:

ganymed_bob/sy120_gbm
ganymed_bob/sy120_gen1

Maybe I am missing something. But actually I dont know how to fix that. Would be great to have your support @nordicjm @maass-hamburg

[tswaehn]

It works, when I put:

.. zephyr:board:: ganymed_bob
.. _ganymed_bob:

Actually I thought the second line should be obsolete with the new macro of first line.

[maass-hamburg]

@kartben pls take a look

[kartben]

Maybe I am missing something. But actually I dont know how to fix that.

@tswaehn there is probably nothing to fix, actually :) With what you have right now, list of supported features will be generated for each available board target.

[tswaehn]

dear @nordicjm, @kartben, @maass-hamburg ;; anything else to change, could we go with the merge?