OMAPDSS: DISPC: Add predecimation limit for TILER based rotations

In OMAP4 and OMAP5 when TILER 2D burst mode is used, a maximum of one line can
be skipped as per the respective TRMs. The MBlockStride OCP signal, which is
sum of ROWINC and image width in memory, is only 17 bits wide. In 2D mode TILER
supports 8192, 16384, 32768 and 65536 values of MBlockStride. In case when 2 or
more lines are skipped the ROWINC value exceeds 65536 resulting in OCP errors.
So, maximum vertical predecimation achievable is 2.

Signed-off-by: Chandrabhanu Mahapatra <cmahapatra@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>