staging: gma500: Fix warning in power.c

 gma_resume_display() wants 'struct pci_dev *' as it's parameter, so lets pass dev->pdev instead of dev. Fixes the following warning.

drivers/staging/gma500/power.c: In function ‘gma_power_begin’:
drivers/staging/gma500/power.c:269:3: warning: passing argument 1 of ‘gma_resume_display’ from incompatible pointer type
drivers/staging/gma500/power.c:99:13: note: expected ‘struct pci_dev *’ but argument is of type ‘struct drm_device *’
Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/gma500/power.c

@@ -266,7 +266,7 @@ bool gma_power_begin(struct drm_device *dev, bool force_on)
 	ret = gma_resume_pci(dev->pdev);
 	if (ret == 0) {
 		/* FIXME: we want to defer this for Medfield/Oaktrail */
-		gma_resume_display(dev);
+		gma_resume_display(dev->pdev);
 		psb_irq_preinstall(dev);
 		psb_irq_postinstall(dev);
 		pm_runtime_get(&dev->pdev->dev);