gpio: change member .dev to .parent

The name .dev in a struct is normally reserved for a struct device
that is let us say a superclass to the thing described by the struct.
struct gpio_chip stands out by confusingly using a struct device *dev
to point to the parent device (such as a platform_device) that
represents the hardware. As we want to give gpio_chip:s real devices,
this is not working. We need to rename this member to parent.

This was done by two coccinelle scripts, I guess it is possible to
combine them into one, but I don't know such stuff. They look like
this:

@@
struct gpio_chip *var;
@@
-var->dev
+var->parent

and:

@@
struct gpio_chip var;
@@
-var.dev
+var.parent

and:

@@
struct bgpio_chip *var;
@@
-var->gc.dev
+var->gc.parent

Plus a few instances of bgpio that I couldn't figure out how
to teach Coccinelle to rewrite.

This patch hits all over the place, but I *strongly* prefer this
solution to any piecemal approaches that just exercise patch
mechanics all over the place. It mainly hits drivers/gpio and
drivers/pinctrl which is my own backyard anyway.

Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Rafał Miłecki <zajec5@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: Alek Du <alek.du@intel.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

include/linux/gpio/driver.h

@@ -20,7 +20,7 @@ struct seq_file;
 /**
  * struct gpio_chip - abstract a GPIO controller
  * @label: for diagnostics
- * @dev: optional device providing the GPIOs
+ * @parent: optional parent device providing the GPIOs
  * @cdev: class device used by sysfs interface (may be NULL)
  * @owner: helps prevent removal of modules exporting active GPIOs
  * @list: links gpio_chips together for traversal
@@ -89,7 +89,7 @@ struct seq_file;
  */
 struct gpio_chip {
 	const char		*label;
-	struct device		*dev;
+	struct device		*parent;
 	struct device		*cdev;
 	struct module		*owner;
 	struct list_head        list;