ARM: OMAP2+: Enable pinctrl dummy states

Enable pinctrl dummy states for all OMAP platforms that don't
populate DT. This allows drivers to be converted to pinctrl
and not generate new warnings on platforms that do not provide
pinctrl data. These platforms already have pinmuxes configured
before the drivers probe.

Signed-off-by: Matt Porter <mporter@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>