Add architecture and scheduler maps

Makes preferring local packages with armv8el and i486 OBS schedulers
work. These mappings armv7hl/armv7tnhl -> armv8el and i486 ->
i586/i686 only affect the "get-preferred-packages" evaluation that is
used when the -p or --prefer-pkgs option is used with the osc build
command.

Signed-off-by: Juha Kallioinen <juha.kallioinen@jollamobile.com>