Refactor env-test deployment structure

Modifies the env_test deployment build and directory structure to
allow for different build configurations with different test suites.
Added a place-holder configuration for n1sdp to enable test cases
to be added for drivers reused from edk2-platforms.

Signed-off-by: Julian Hall <julian.hall@arm.com>
Change-Id: I7a7a7cf811ae224ec75a83ae200f897bef84e5ae
19 files changed