ARM: OMAP5: dmm: Create a tiler trap section.

ARM: OMAP5: dmm: Create a tiler trap section.

The unmapped entries in tiler space are set with
values 0xFF. So creating a DMM section of
size 16MB at 0xFF000000 with ADDRSPACE set to 0x2.

This way all the unmapped entry accesses to tiler
will be trapped by the EMIF and a error response
is sent to the L3 interconnect. L3 errors are
inturn reported to MPU.

Note that here the tiler trap section is overlapping
with the actual ddr physical space and we lose 16MB
out of the total 2GB.

Signed-off-by: R Sricharan <r.sricharan@ti.com>