ARM: S3C24XX: Remove unused GPIO definitions for Openmoko GTA02 board

mach-s3c24xx/include/mach/gta02.h header file contains defines
which are now not used anywhere, remove them.

Cc: Nelson Castillo <arhuaco@freaks-unidos.net>
Signed-off-by: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>