of_gpio_chip structure and moves the relevant
fields into struct gpio_chip (conditional on CONFIG_OF_GPIO).  This move
simplifies the existing code and prepares for adding automatic device tree
support to existing drivers.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Bill Gatliff <bgat@billgatliff.com>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jean Delvare <khali@linux-fr.org>
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