i2c: move i2c_omap's probe function to .devinit.text

A pointer to omap_i2c_probe is passed to the core via
platform_driver_register and so the function must not disappear when the
.init sections are discarded.  Otherwise (if also having HOTPLUG=y)
unbinding and binding a device to the driver via sysfs will result in an
oops as does a device being registered late.

An alternative to this patch is using platform_driver_probe instead of
platform_driver_register plus removing the pointer to the probe function
from the struct platform_driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Kalle Jokiniemi <ext-kalle.jokiniemi@nokia.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Richard Woodruff <r-woodruff2@ti.com>
Cc: chandra shekhar <x0044955@ti.com>
Cc: Jason P Marini <jason.marini@gmail.com>
Cc: Syed Mohammed Khasim  <x0khasim@ti.com>
Cc: Jarkko Nikula <jarkko.nikula@nokia.com>
Cc: Juha Yrjola <juha.yrjola@solidboot.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>