gpio: 74x164: Remove non-DT support

Commit 20bc4d5d565159eb2b942bf4b7fae86fba94e32c
(gpio: 74x164: Add support for the daisy-chaining) introduce check
for DT for the driver, so driver cannot be used without DT.
There are no in-tree users of this driver, so remove non-DT support
completely.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Acked-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>