gpu-compute: Remove unneeded Request::setVirt call

gpu-compute: Remove unneeded Request::setVirt call

This sets the members of a Request object to the values they
already hold, except the atomicOpFunctor which is set to
nullptr. This call introduces a bug for atomics and is not
useful for non-atomic requests. This changeset is also
adding the wave PC and instruction sequence number to the
Request object.

Change-Id: I62f7b4a597483b0aa848a0cfbc72181e1063f56a
Reviewed-on: https://gem5-review.googlesource.com/11549
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>