ARM: OMAP3: remove deprecated CONFIG_OMAP_IOMMU_IVA2

CONFIG_OMAP_IOMMU_IVA2 was defined originally to avoid conflicting
usage by tidspbridge and other iommu users. The same can be achieved
by marking the DT node disabled, so remove this obsolete flag and
the corresponding hwmod data can be enabled.

Cc: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch>
[s-anna@ti.com: revise commit log]
Signed-off-by: Suman Anna <s-anna@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>