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.

Cc: Lee Jones <lee@kernel.org>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mmc@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>