ARM: s3c24xx: drop s3c-camif setup platform code

The s3c-camif driver setup platform code does not have any users so it
can be safely removed.

Along with the code W=1 compile warnings go away:

    arch/arm/mach-s3c24xx/setup-camif.c:28:5: warning: no previous prototype for 's3c_camif_gpio_get' [-Wmissing-prototypes]
    arch/arm/mach-s3c24xx/setup-camif.c:56:6: warning: no previous prototype for 's3c_camif_gpio_put' [-Wmissing-prototypes]

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>