iris: Force device local memory for u_upload_mgr buffers

We try to place persistent/coherent buffers from the application in system memory, because they want the CPU-GPU coherency.

However, our internal u_upload_mgr buffers are also flagged persistent + coherent, but we absolutely want most of them in device local memory.

Tested-by: Luis Felipe Strano Moraes luis.strano@intel.com