AMD flogged its mobile graphics division in 2009 to Qualcomm, which uses the technology in a mobile GPU called Adreno, an anagram of Radeon. It was a classic own goal because the mobile market was just starting to take off.
However according to ITworld Koduri said it could make a mobile GPU as part of a partnership or a licensing deal, but otherwise has no active plans to build an end product for mobile devices.
AMD could make one as part of a large custom chip deal, potentially worth millions of dollars. To do that of course it would need a mobile partner willing to take a gamble. The sort of thing that AMD would do is like it did for Microsoft’s Xbox or PlayStation 4.
There is nothing to stop AMD breaking down its GPUs into smaller cores and tweaking them so they use less power. They should be able to manage 4K video.
However AMD would have to look at Nvidia’s GPUs which are seen as too power hungry to do much good. Its biggest rival is Imagination, with its Mali graphics used in Samsung's Galaxy handsets.
A mobile AMD chip might enable some radical technology improvements which might make a partner more interested. However it is also unlikely that anyone is going to take up Koduri’s offer.