ARM: SAMSUNG: cleanup mach/gpio-fns.h gpio-track.h and gpio-nrs.h

remove <mach/gpio-fns.h>, <mach/gpio-track.h> and <plat/gpio-fns.h>

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>