mfd: ezx-pcap: Don't pass pcap pointer as subdev drvdata.

Abusing subdev drvdata is not needed anymore, as all pcap subdevs are now
retrieving the pcap pointer from their parent device.

This change removes a leftover coming from early versions of ezx-pcap and its
subdevs drivers.
Signed-off-by: Antonio Ospite <ospite@studenti.unina.it>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/ezx-pcap.c

@@ -387,7 +387,6 @@ static int __devinit pcap_add_subdev(struct pcap_chip *pcap,
 	pdev = platform_device_alloc(subdev->name, subdev->id);
 	pdev->dev.parent = &pcap->spi->dev;
 	pdev->dev.platform_data = subdev->platform_data;
-	platform_set_drvdata(pdev, pcap);
 
 	return platform_device_add(pdev);
 }