Softbank is planning to sell 25% of ARM, its processor IP subsidiary, to a new Saudi Arabian-backed $100bn investment fund, Mubadala. The stake should be worth about worth about $8bn – the Japanese operator paid $32bn for ARM about six months ago. Not long after the ARM deal, Softbank announced an ambitious plan to set up the Softbank Vision Fund to help its CEO, Masayoshi Son, invest more easily in technology projects worldwide. Son was a big hit at Mobile World Congress with his futuristic views on a future driven by 5G, robotics, AI and ‘super-intelligence’. But turning such ideas from slideware into reality takes large amounts of money – more than Softbank, or ARM (a strategic element in Son’s…