configs: fwu: remove FWU configs for metadata V2 support

Support is to be added in the following commits for the FWU metadata
version 2. Disable the FWU feature on platforms that enable it for the
V2 addition work.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Tested-by: Michal Simek <michal.simek@amd.com>