util: Update ROCm to 1.6.4 in gcn Dockerfile, install HIP by .deb

util: Update ROCm to 1.6.4 in gcn Dockerfile, install HIP by .deb

Previously, we were using ROCm 1.6.2 as there were issues with some of
the machine learning applications that weren't present on 1.6.2.
However, after re-running them we've found that they, and all other
applications previously tested, run to completion.

Additionally, there have been patches to enable BLIT kernels which made
it so we no longer need to build HIP and MIOpen differently for APU and
DGPU code. This allows us to install HIP directly from the .deb packages
instead of from source. Installing from the .deb packages also avoid the
hipDeviceSynchronize() bug. Finally, this makes it so most GPU programs
can be run as-is without modifications to remove hipMalloc/hipMemcpy
calls as was done previously.

Change-Id: Ic61b09ed200b19f759d891487cde874abd607537
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/37675
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>