Imagination licences a core to a customer (such as Intel) so that they can make a product. The customer then decides how to support this product and what will be supported on it. Different customers want different levels of involvement from Imagination to provide drivers for their product and to deliver these drivers to end users. In this case, Intel have chosen to control distribution of drivers themselves which means that Imagination don't distribute the drivers - I can't give you any. If there are none available from Intel then you should take this up with them.
The agreements concerning how drivers are written, for which platforms and who writes them etc. are confidential and not something I can talk about on this forum.
This issue is something we're aware of, have discussed and something I've even investigated myself so I appreciate your frustration and will pass on your concerns. I can't help more than that, I'm afraid.