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>
diff --git a/drivers/gpio/gpio-em.c b/drivers/gpio/gpio-em.c
index 6bca1e1..c3ca2b1 100644
--- a/drivers/gpio/gpio-em.c
+++ b/drivers/gpio/gpio-em.c
@@ -103,7 +103,7 @@
 	struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
 
 	if (gpiochip_lock_as_irq(&p->gpio_chip, irqd_to_hwirq(d))) {
-		dev_err(p->gpio_chip.dev,
+		dev_err(p->gpio_chip.parent,
 			"unable to lock HW IRQ %lu for IRQ\n",
 			irqd_to_hwirq(d));
 		return -EINVAL;
@@ -332,7 +332,7 @@
 	gpio_chip->request = em_gio_request;
 	gpio_chip->free = em_gio_free;
 	gpio_chip->label = name;
-	gpio_chip->dev = &pdev->dev;
+	gpio_chip->parent = &pdev->dev;
 	gpio_chip->owner = THIS_MODULE;
 	gpio_chip->base = -1;
 	gpio_chip->ngpio = ngpios;