cpu: Get rid of the BaseCPU UnifiedTLB parameter.

This parameter is not (and as far as I can tell has never been) used,
and is guarded with a check of TARGET_ISA.

Change-Id: I71f4894228391e2024dab20e1bf2618dcea4f421
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/52487
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/cpu/BaseCPU.py

@@ -150,8 +150,6 @@ class BaseCPU(ClockedObject):
     workload = VectorParam.Process([], "processes to run")
 
     mmu = Param.BaseMMU(ArchMMU(), "CPU memory management unit")
-    if buildEnv['TARGET_ISA'] == 'power':
-        UnifiedTLB = Param.Bool(True, "Is this a Unified TLB?")
     interrupts = VectorParam.BaseInterrupts([], "Interrupt Controller")
     isa = VectorParam.BaseISA([], "ISA instance")