net: ieee802154: mcr20a: convert to use maple tree register cache

The maple tree register cache is based on a much more modern data structure
than the rbtree cache and makes optimisation choices which are probably
more appropriate for modern systems than those made by the rbtree cache.

Signed-off-by: Bo Liu <liubo03@inspur.com>
Message-ID: <20240202064611.39346-1-liubo03@inspur.com>
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>