Revert "clkdev: remove CONFIG_CLKDEV_LOOKUP"

Revert "clkdev: remove CONFIG_CLKDEV_LOOKUP"

This reverts commit d08932bb6e38 which is
commit 2f4574dd6dd19eb3e8ab0415a3ae960d04be3a65 upstream.

It is reported to cause build errors in m68k, so revert it.

Link: https://lore.kernel.org/r/68b0559e-47e8-4756-b3de-67d59242756e@roeck-us.net
Reported-by: Guenter Roeck <linux@roeck-us.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ross Burton <ross.burton@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>