OMAP4: DSS2: Add hwmod device names for OMAP4.

Add hwmod device names for OMAP4; this enables device build for omap4 dss
hwmod IPs.

Signed-off-by: Sumit Semwal <sumit.semwal@ti.com>
Signed-off-by: Mayuresh Janorkar <mayur@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>