ramips: drop remaining m25p,chunked-io from DTS

ramips: drop remaining m25p,chunked-io from DTS

This option was a spi nor hack which is dropped in commit bcf4a5f474d1
("ramips: remove chunked-io patch and set spi->max_transfer_size instead")

Most of it has already been removed in
be2b61e4f1ec ("ramips: drop m25p,chunked-io from dts")

It seems all current usages were added after that. Remove them.

Cc: Chuanhong Guo <gch981213@gmail.com>
Reported-by: Sungbo Eo <mans0n@gorani.run>
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>