A deal to supply a major iPhone component can be the making of a vendor, but over-reliance on Apple certainly comes with huge risk if the company goes cold. Imagination Technologies and Qualcomm have both seen Apple looking for alternatives to their products – Imagination’s graphics processor unit (GPU) cores and Qualcomm’s smartphone modems – and are now also embroiled in disputes. In both cases, Apple has been hitting back vociferously. It piled on more troubles for Imagination by claiming the UK firm was warned about the ending of their contract long before it informed the markets. And its lawsuits against Qualcomm threaten to undermine the basis of the chip giant’s business model, provoking an escalated response last week when…