Input: s3c24xx_ts - Implement generic GPIO configuration callback

This patch implements generic GPIO configuration function in Samsung
touchscreen driver. And makes the touchscreen driver s3c24xx-ts.c
generic to all the Samsung SoCs.

Signed-off-by: Naveen Krishna Ch <ch.naveen@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
[ben-linux@fluff.org: fixed title ]
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Acked-by: Dmitry Torokhov <dtor@mail.ru>