ARM: w1-gpio: fix erroneous gpio requests

Fix regression introduced by commit d2323cf773 ("onewire: w1-gpio: add
ext_pullup_enable pin in platform data") which added a gpio entry to the
platform data, but did not add the required initialisers to the board
files using it. Consequently, the driver would request gpio 0 at probe,
which could break other uses of the corresponding pin.

On AT91 requesting gpio 0 changes the pin muxing for PIOA0, which, for
instance, breaks SPI0 on at91sam9g20.

Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/arch/arm/mach-at91/board-stamp9g20.c b/arch/arm/mach-at91/board-stamp9g20.c
index a033b8d..869cbec 100644
--- a/arch/arm/mach-at91/board-stamp9g20.c
+++ b/arch/arm/mach-at91/board-stamp9g20.c
@@ -188,6 +188,7 @@
 static struct w1_gpio_platform_data w1_gpio_pdata = {
 	.pin		= AT91_PIN_PA29,
 	.is_open_drain	= 1,
+	.ext_pullup_enable_pin	= -EINVAL,
 };
 
 static struct platform_device w1_device = {