plat(n1sdp): initial commit of N1SDP platform port

This patch allows TFTF to run on N1SDP in a limited manner and is still in
development, some tests are disabled using the file
plat/arm/n1sdp/tests_to_skip.txt.

The major known issue now is with PSCI commands waking up and powering
down cores, and SGIs do not wake up powered off cores.

Build command: "make CROSS_COMPILE=aarch64-none-elf- PLAT=n1sdp tftf"

To run TFTF on N1SDP, copy tftf.bin to the /SOFTWARE directory on the SD
card and edit the images.txt file to load tftf.bin instead of uefi.bin.

Signed-off-by: John Powell <john.powell@arm.com>
Change-Id: I897ba665306413c594544d6a231555475e7c8111
8 files changed