sim: Fix clashing stat names in TickedObject and Ticked

sim: Fix clashing stat names in TickedObject and Ticked

Change tickCycles numCycles stat name to totalTickCycles os as not to
clash with the name of the tickCycles stat of the same class.
Declared the params passed to the TickedObject constructer as const.
Call ClockedObject::regStats() from the TickedObject::regStats to
ensure the correct initialization of the base class (ClockedObject)
stats

Change-Id: I6cf5bbe10fa27f2ad0e31d9f70ec3be47fe41455
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/3964
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>