fix(cpufeat): resolve build errors due to compiler optimization
Currently most of the architectural feature build flags are set
to 2(FEATURE_STATE_CHECK) for fvp platform only.
However other platforms still configure them by default to 0, which
would lead to build failures in cases when compiler configured
to build TF-A with zero optimization (CFLAGS='-O0').
This patch addresses such build issues and thereby resolves the failures
seen under CI-l3 test_configurations.