dm: core: device: add function: dev_get_driver_ops()

This commit extends the driver model device's API by function:
- dev_get_driver_ops()

And this function returns the device's driver's operations if given:
- dev pointer, is non-NULL
- dev->driver->ops pointer, is non-NULL
in other case the, the NULL pointer is returned.

Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
Cc: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>

drivers/core/device.c

@@ -499,6 +499,14 @@ ulong dev_get_driver_data(struct udevice *dev)
 	return dev->driver_data;
 }
 
+const void *dev_get_driver_ops(struct udevice *dev)
+{
+	if (!dev || !dev->driver->ops)
+		return NULL;
+
+	return dev->driver->ops;
+}
+
 enum uclass_id device_get_uclass_id(struct udevice *dev)
 {
 	return dev->uclass->uc_drv->id;