feat(rdfremont): add support for RD-Fremont-Cfg2

Add board support for RD-Fremont-Cfg2 platform, which is a quad chip
variant of RD-Fremont. Each chip has reduced core count of four CPUs as
compared to single chip RD-Fremont platform.

Signed-off-by: Pranav Madhu <pranav.madhu@arm.com>
Signed-off-by: Rohit Mathew <rohit.mathew@arm.com>
Change-Id: I9b79f0eef210afecaa15e381414479027617e44a
7 files changed