ASoC: samsung: fix neo1973-wm8753 compilation

Commit b2ca7871 (ARM: S3C24XX: make gta02.h local) already replaced
the GTA02_GPIO_* constants in neo1973-wm8753.c but forgot to remove the
inclusion of mach/gta02.h before moving the file out of mach/.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>