refactor(build): reorder arch features handling

With commit@f5211420b(refactor(cpufeat): refactor arch feature build
options all mandatory options are enabled with
'make_helpers/arch_features.mk'

However the commit makes it impossible for enabling of mandatory
features through command line and platform make files, So re-order
handling of mandatory features in 'make_helpers/arch_features.mk'

Use below order to enable mandatory features.

1.) first enable mandatory features by arch major/minor
2.) check if features were not earlier defined in platform makefile or
through cmdline if defined earlier don't initialise them to '0' but
retain their values from prior initialisation.

Change-Id: Icea3180c9dda0cd6e0b59316add9f3290ae51972
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
1 file changed