fix(build): remove duplicated include order

Commit(3547270f5 refactor(build): reorder platform Makefile
evaluation) re-ordered platform makefile inclusion before
arch_features evaluations, but then it fails to remove the dependency
that were moved and thus have double evaluation of some build
variables apparently this breaks BUILD_PLAT.

Additionally remove duplicate checks in SPMD similar checks are in
place in main level makefile.

Change-Id: I5a71624fc43977054467ec6502ce359fb1d08838
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
2 files changed