Add DT data for OMAP2 display subsystem, which contains the following
blocks:

dss - the wrapper/glue for the display modules
dispc - display controller
rfbi - MIPI DBI encoder
venc - analog TV encoder
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>