Revert "cpu: fix how a thread starts up in MinorCPU"

This reverts commit 02dafc5498750d9734ba8f2a1608a846f90b71d1.
The commit was part of a patchset which broke MinorCPU regressions
(switcheroo)

Change-Id: I0a8098fc71abe5838014e587dbe372b258d8aa9f
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18604
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
6 files changed