ARM: dts: OMAP3: Update ISP IOMMU node

Update the IOMMU node for the camera subsystem as per the
OMAP IOMMU bindings.

Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch>
[s-anna@ti.com: corrected interrupt number]
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>