net: Move the VCI and client arch values to Kconfig

We have a bunch of boards that define their vendor class identifier and
client archs in the board files or in the distro config. Move everything
to the generic Kconfig options.

We're missing the distinction between i386 and x86_64, as I couldn't find
any config variable that would tell us the difference. Is that really important
to people? I guess not, so I left it out.

Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Tom Rini <trini@konsulko.com>