amends b4525b3407, which gives no indication for why this was done.
judging by other tests, it wasn't cargo-culted. i presume it was just
about disabling debug-and-release, and the debug choice was arbitrary.
the central system nowadays does the same, just that it uses release.
amends 1533bfc5fc, which certainly _was_ cargo-culted from the former.
as a side effect, this removes some other CONFIG manipulations which are
handled centrally or are wholly ineffective nowadays.
Change-Id: Ib9af2837925a2f19af05506e798a26d363635735
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
aaed0530fd