media: s5k4ecgx: Delete driver

This driver was until the previous patch unused in the kernel
and depended on platform data that no board was defining.
As no users can be proven to exist, delete the driver.

Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Alim Akhtar <alim.akhtar@samsung.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Suggested-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>