omap3: cm-t3517: add board specific get_board_rev()

CM-T3517 has several HW revisions.
Add board specific get_board_rev() callback to retrieve revision number.

Signed-off-by: Dmitry Lifshitz <lifshitz@compulab.co.il>
Reviewed-by: Igor Grinberg <grinberg@compulab.co.il>
1 file changed