ARM: OMAP4: hwmod data: add DEBUGSS skeleton

Add a skeleton hwmod for the DEBUGSS and associated interconnect data.
This is a basic set of data that will need further additions as
further DEBUGSS information becomes available.

Signed-off-by: Benoît Cousson <b-cousson@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>