feat(neoverse-rd): add DRAM layout for third gen platforms

Given the differences in memory map of the third generation reference
design platforms, it is necessary to move away from the common DRAM
layout present as part of arm_def.h. Therefore, introduce definitions
and necessary carveouts within DRAM to define a new DRAM layout for
these platforms.

Signed-off-by: Rohit Mathew <rohit.mathew@arm.com>
Change-Id: I79af066f41259f147febdc3c00447db5be995799
3 files changed