docs: We pass all target slots to the handler
docs: We pass all target slots to the handler

The handler is called only once for the entire update.
Thus a list of all target slots needs to be passed.

Signed-off-by: Enrico Jorns <a2e5f936c390f36494e46e71bcfbe365bb1e8c49@pengutronix.de>

jluebbe/rauc,rauc/rauc,ejoerns/rauc,ejoerns/rauc,rauc/rauc,ejoerns/rauc,jluebbe/rauc,jluebbe/rauc,rauc/rauc