OMAP2: Add funcs for writing SMS_ROT_* registers

SMS_ROT_* registers are used by VRFB rotation engine.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Paul Walmsley <paul@pwsan.com>