arm: omap3: cm-t35: add support for cm-t3730

cm-t3730 is basically the same board as cm-t35,
but has AM/DM3730 SoC assembled and therefore some changes are required.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Acked-by: Mike Rapoport <mike@compulab.co.il>
[tony@atomide.com: updated for init_irq cleanup as noted by khilman@ti.com]
Signed-off-by: Tony Lindgren <tony@atomide.com>