[media] omap3isp: Rename regulators to better suit the Device Tree

Rename VDD_CSIPHY1 as vdd-csiphy1 and VDD_CSIPHY2 as vdd-csiphy2.

Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>