Add AXI parameter in cva6 config, keep AXI master structs in ariane and slave in SOC

Created by: JeanRochCoulon

The axi stuctures were declared twice in the RTL. This PR declare master structures in ariane_axi package and slave structures in ariane_axi_soc package. In parallel, the Ariane AXI configuration is done thanks to parameters declared in cva6 config.