i2c: gpio: move header to platform_data

This header only contains platform_data. Move it to the proper directory.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: James Hogan <jhogan@kernel.org>
Acked-by: Greg Ungerer <gerg@uclinux.org>