OMAP4: hwmod data: Add watchdog timer

Add watchdog timer hwmod data for OMAP4 chip

Note: wd_timer3 in enabled in the hwmod list but it is
not yet supported by the watchdog driver.

Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Signed-off-by: Charulatha V <charu@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>