armv8: K3: j721e: Add DSP internal memory regions in MMU table

The A72 U-Boot code supports early load and boot of a number of
remote processors including the C66_0 and C66_1 DSPs. The current
code supports only loading into the DDR regions which were already
given the appropriate memory attributes. The C66 DSPs also have L1
and L2 internal memory regions that can behave as normal-memories.

Add a new entry to the J721E MMU table covering these regions with
the appropriate memory attributes to allow the A72 U-Boot code to
support loading directly into these memory regions.

Signed-off-by: Suman Anna <s-anna@ti.com>