drivers: Enable building of Kirkwood drivers for mach-mvebu

With the move of kirkwood into mach-mvebu, drivers Kconfig need
tweeking to allow the kirkwood specific drivers to be built.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Mark Brown <broonie@linaro.org>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Bryan Wu <cooloney@gmail.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>