plat/arm/rdinfra: Add initial platform support for RD-N1-Edge

RD-N1-Edge platform consists of two clusters of four CPU's
each. The FVP for this platform does not support system suspend and
resume functionality as there is no wakeup source supported. So all
the system suspend and resume related tests are skipped.

Change-Id: I33649c7c67023127e736c760bf0ec4193c95ed1a
Signed-off-by: Chandni Cherukuri <chandni.cherukuri@arm.com>