qup_i2c: Set parent device to enable runtime PM support for clients

Register the current device as parent of the adaptor device in order to
allow the client drivers to use runtime PM.  Client drivers can vote to
enable and disable clocks as needed.

Change-Id: Ie2d6b96ab0cbe5af56b4da0f5f18b37d0495e053
Acked-by: Christian Bolis <cbolis@qti.qualcomm.com>
Signed-off-by: Kenneth Heitke <kheitke@codeaurora.org>
diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index b562350..717f763 100644
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -1305,6 +1305,7 @@
 		"QUP I2C adapter",
 		sizeof(dev->adapter.name));
 	dev->adapter.nr = pdev->id;
+	dev->adapter.dev.parent = &pdev->dev;
 	if (pdata->msm_i2c_config_gpio)
 		pdata->msm_i2c_config_gpio(dev->adapter.nr, 1);