[ARM] 4671/1: ep93xx: remove obsolete gpio_line_* operations

With the new GPIO methods in place the old gpio_line_* methods are redundant,
so this patch finally removes the old legacy gpio_line_* wrappers.

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>
Acked-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>