Rename sycl::INTEL::gpu to sycl::intel::gpu

[sapoluri]

For the latest official release, the namespace is declared as sycl::INTEL::gpu. While all previous releases as well as some documentation refers to it as sycl::intel::gpu.

Please use one or the other.

[AlexeySachkov]

Hi @sapoluri, thanks for the report

If I understand correctly, intel -> INTEL change was done in order to align with extensions mechanism from upcoming SYCL 2020, in particular see: #2231 (comment).

Looking at #2246 I don't see documentation updated, tagging @jbrodman and @Pennycook for awareness

[github-actions]

This issue is stale because it has been open 180 days with no activity. Remove stale label or comment or this will be automatically closed in 30 days.

[alexbatashev]

The extension naming scheme was updated to conform to latest SYCL 2020 specification. Please, re-open if you disagree.