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: NBenoit Cousson <b-cousson@ti.com>
Signed-off-by: NCharulatha V <charu@ti.com>
Signed-off-by: NKevin Hilman <khilman@deeprootsystems.com>