arch-arm: Remove unnecessary case in ISA::readMiscReg

Change-Id: I8b95a75fbfec2626fbe8b455ae9b3f30acda538f
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Richard Cooper <richard.cooper@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/70564
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/arch/arm/isa.cc

@@ -567,8 +567,6 @@ ISA::readMiscReg(RegIndex idx)
             l2ctlr.numCPUs = tc->getSystemPtr()->threads.size() - 1;
             return l2ctlr;
         }
-      case MISCREG_DBGDSCRint:
-        return readMiscRegNoEffect(MISCREG_DBGDSCRint);
       case MISCREG_ISR:
       case MISCREG_ISR_EL1:
         {