drm/panfrost: simplify getting .driver_data

We should get 'driver_data' from 'struct device' directly. Going via
platform_device is an unneeded step back and forth.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210920090522.23784-6-wsa+renesas@sang-engineering.com

drivers/gpu/drm/panfrost/panfrost_device.c

@@ -398,8 +398,7 @@ void panfrost_device_reset(struct panfrost_device *pfdev)
 #ifdef CONFIG_PM
 int panfrost_device_resume(struct device *dev)
 {
-	struct platform_device *pdev = to_platform_device(dev);
-	struct panfrost_device *pfdev = platform_get_drvdata(pdev);
+	struct panfrost_device *pfdev = dev_get_drvdata(dev);
 
 	panfrost_device_reset(pfdev);
 	panfrost_devfreq_resume(pfdev);
@@ -409,8 +408,7 @@ int panfrost_device_resume(struct device *dev)
 
 int panfrost_device_suspend(struct device *dev)
 {
-	struct platform_device *pdev = to_platform_device(dev);
-	struct panfrost_device *pfdev = platform_get_drvdata(pdev);
+	struct panfrost_device *pfdev = dev_get_drvdata(dev);
 
 	if (!panfrost_job_is_idle(pfdev))
 		return -EBUSY;