mfd: Remove toshiba tmio drivers

Four separate mfd drivers are in the "tmio" family, and all of
them were used in now-removed PXA machines (eseries, tosa, and
hx4700), so the mfd drivers and all its children can be removed
as well.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230105134622.254560-19-arnd@kernel.org