gpio: zynq: Fix problem with unbalanced pm_runtime_enable

Add missing pm_runtime_disabled to remove().

Error log:
root@zynqmp:~# modprobe gpio_zynq
root@zynqmp:~# lsmod
    Not tainted
gpio_zynq 7086 0 - Live 0xffffffbffc00a000
root@zynqmp:~# rmmod gpio_zynq
root@zynqmp:~# lsmod
    Not tainted
root@zynqmp:~# modprobe gpio_zynq
[  246.924438] zynq-gpio ff0a0000.gpio: Unbalanced pm_runtime_enable!
root@zynqmp:~# rmmod gpio_zynq
root@zynqmp:~# lsmod
    Not tainted

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpio-zynq.c b/drivers/gpio/gpio-zynq.c
index 2e87c4b..a788823 100644
--- a/drivers/gpio/gpio-zynq.c
+++ b/drivers/gpio/gpio-zynq.c
@@ -757,6 +757,7 @@
 	gpiochip_remove(&gpio->chip);
 	clk_disable_unprepare(gpio->clk);
 	device_set_wakeup_capable(&pdev->dev, 0);
+	pm_runtime_disable(&pdev->dev);
 	return 0;
 }