generic: 6.12: add hack patch for transition to new partition bindings

generic: 6.12: add hack patch for transition to new partition bindings

Commit fa0f130764 ("generic: 6.12: update block NVMEM driver") switched
to the upstream DT bindings for block partitions.

Bring back the old/legacy downstream way to assign the OF node to a
block device or partition in order to allow sharing a single DTS for
both, Linux 6.6 (which exclusively uses the old/legacy binding) and
Linux 6.12 (which will now support both, new/upstream binding and the
old/legacy binding).

Once we drop Linux 6.6 and all boards have been converted to the new
binding we can drop this patch.

Signed-off-by: Daniel Golle <[email protected]>