make reset control optional for i.MX27
The patch "[media] coda: add reset control support" introduced a build failure
if CONFIG_RESET_CONTROLLER is disabled:
    drivers/media/platform/coda.c:3734:2: error: implicit declaration of
     function 'devm_reset_control_get'
Since not all SoCs containing CODA VPUs do have a system reset controller,
use devm_reset_control_get_optional to make it optional.
Reported-by: Shawn Guo <shawn.guo@linaro.org>
Reported-by: Olof's autobuilder <build@lixom.net>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
                return ret;
        }
 
-       dev->rstc = devm_reset_control_get(&pdev->dev, NULL);
+       dev->rstc = devm_reset_control_get_optional(&pdev->dev, NULL);
        if (IS_ERR(dev->rstc)) {
                ret = PTR_ERR(dev->rstc);
-               if (ret == -ENOENT) {
+               if (ret == -ENOENT || ret == -ENOSYS) {
                        dev->rstc = NULL;
                } else {
                        dev_err(&pdev->dev, "failed get reset control: %d\n", ret);