pwm: Fill in missing .owner fields

Some drivers don't set the .owner fields of the struct device_driver or
struct pwm_ops, which causes the module usage count to become wrong.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
diff --git a/drivers/pwm/pwm-mxs.c b/drivers/pwm/pwm-mxs.c
index 6489a4b..2c77b81 100644
--- a/drivers/pwm/pwm-mxs.c
+++ b/drivers/pwm/pwm-mxs.c
@@ -182,6 +182,7 @@
 static struct platform_driver mxs_pwm_driver = {
 	.driver = {
 		.name = "mxs-pwm",
+		.owner = THIS_MODULE,
 		.of_match_table = of_match_ptr(mxs_pwm_dt_ids),
 	},
 	.probe = mxs_pwm_probe,