Zephyr provides a feature to hook in custom menuconfig implementations
by setting EXTRA_KCONFIG_TARGETS and then defining the corresponding
command to invoke as EXTRA_KCONFIG_TARGET_COMMAND_FOR_<target>.
This feature is broken with sysbuild because sysbuild will try to create
multiple custom targets with identical names.
This commit fix the sysbuild handling of extra kconfig targets.
Signed-off-by: Torsten Rasmussen <Torsten.Rasmussen@nordicsemi.no>
1bea5fcacb