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>

drivers/gpio/gpio-vr41xx.c

@@ -139,7 +139,7 @@ static void unmask_giuint_low(struct irq_data *d)
 static unsigned int startup_giuint(struct irq_data *data)
 {
 	if (gpiochip_lock_as_irq(&vr41xx_gpio_chip, data->hwirq))
-		dev_err(vr41xx_gpio_chip.dev,
+		dev_err(vr41xx_gpio_chip.parent,
 			"unable to lock HW IRQ %lu for IRQ\n",
 			data->hwirq);
 	/* Satisfy the .enable semantics by unmasking the line */
@@ -542,7 +542,7 @@ static int giu_probe(struct platform_device *pdev)
 	if (!giu_base)
 		return -ENOMEM;
 
-	vr41xx_gpio_chip.dev = &pdev->dev;
+	vr41xx_gpio_chip.parent = &pdev->dev;
 
 	ret = gpiochip_add(&vr41xx_gpio_chip);
 	if (!ret) {