gpu-compute: remove recvToken from GM pipe exec

gpu-compute: remove recvToken from GM pipe exec

Tokens were previously acquired in GM pipe exec but has been moved to
acqCoalescerToken. This removes the extraneous code which was acquiring
tokens twice, causing them to be depleted and triggering an assertion.

Change-Id: Ic92de8f06cc85828b29c69790bdadde057ef1777
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/29916
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>