Input: gpio-keys - use IRQF_SHARED

There is nothing that disallows gpio-keys to share it's IRQ line
w/ other drivers. Make it use IRQF_SHARED in request_irq().

An example of other driver with which I'd like to share IRQ line
for GPIO buttons is ledtrig-gpio.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index a88aff3..77d1309 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -147,6 +147,7 @@
 		}
 
 		error = request_irq(irq, gpio_keys_isr,
+				    IRQF_SHARED |
 				    IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
 				    button->desc ? button->desc : "gpio_keys",
 				    bdata);