Bug#1082816: petsc: enable AMD GPU support

[Drew Parsons]

Source: petsc
Followup-For: Bug #1082816

Hi Cory, I have questions.

How does the GPU support operate (from the perspective of the end
user)?  Is it simply compiled into the existing libraries as an
additional capability?  Is the GPU support activated at runtime?  That
is, do all client packages remain operational as they are and
automatically gain from the speed up if executed on GPU-supporting
hardware? 

Is the GPU support available for all our CPU architectures?

Drew