cpu: fix bimodal predictor to use correct global history reg
cpu: fix bimodal predictor to use correct global history reg

A small bug in the bimodal predictor caused significant degradation in
performance on some benchmarks. This was caused by using the wrong
globalHistoryReg during the update phase. This patches fixes the bug
and brings the performance to normal level.

SanchayanMaity/gem5,aclifton/cpeg853-gem5,rallylee/gem5,gem5/gem5,sobercoder/gem5,gem5/gem5,zlfben/gem5,rjschof/gem5,qizenguf/MLC-STT,gedare/gem5,powerjg/gem5-ci-test,TUD-OS/gem5-dtu,KuroeKurose/gem5,sobercoder/gem5,zlfben/gem5,sobercoder/gem5,SanchayanMaity/gem5,KuroeKurose/gem5,briancoutinho0905/2dsampling,austinharris/gem5-riscv,rallylee/gem5,rallylee/gem5,SanchayanMaity/gem5,HwisooSo/gemV-update,cancro7/gem5,aclifton/cpeg853-gem5,KuroeKurose/gem5,kaiyuanl/gem5,sobercoder/gem5,cancro7/gem5,rjschof/gem5,sobercoder/gem5,Weil0ng/gem5,gem5/gem5,powerjg/gem5-ci-test,powerjg/gem5-ci-test,kaiyuanl/gem5,austinharris/gem5-riscv,qizenguf/MLC-STT,KuroeKurose/gem5,rallylee/gem5,cancro7/gem5,rallylee/gem5,zlfben/gem5,aclifton/cpeg853-gem5,KuroeKurose/gem5,briancoutinho0905/2dsampling,sobercoder/gem5,cancro7/gem5,kaiyuanl/gem5,austinharris/gem5-riscv,aclifton/cpeg853-gem5,gem5/gem5,briancoutinho0905/2dsampling,kaiyuanl/gem5,HwisooSo/gemV-update,markoshorro/gem5,briancoutinho0905/2dsampling,Weil0ng/gem5,Weil0ng/gem5,gem5/gem5,SanchayanMaity/gem5,markoshorro/gem5,markoshorro/gem5,zlfben/gem5,austinharris/gem5-riscv,KuroeKurose/gem5,TUD-OS/gem5-dtu,cancro7/gem5,zlfben/gem5,SanchayanMaity/gem5,Weil0ng/gem5,gedare/gem5,SanchayanMaity/gem5,markoshorro/gem5,cancro7/gem5,markoshorro/gem5,sobercoder/gem5,rallylee/gem5,gedare/gem5,powerjg/gem5-ci-test,rallylee/gem5,HwisooSo/gemV-update,HwisooSo/gemV-update,powerjg/gem5-ci-test,zlfben/gem5,austinharris/gem5-riscv,kaiyuanl/gem5,gedare/gem5,qizenguf/MLC-STT,zlfben/gem5,rjschof/gem5,qizenguf/MLC-STT,briancoutinho0905/2dsampling,markoshorro/gem5,powerjg/gem5-ci-test,TUD-OS/gem5-dtu,gem5/gem5,rjschof/gem5,kaiyuanl/gem5,rjschof/gem5,briancoutinho0905/2dsampling,Weil0ng/gem5,qizenguf/MLC-STT,gedare/gem5,kaiyuanl/gem5,TUD-OS/gem5-dtu,HwisooSo/gemV-update,TUD-OS/gem5-dtu,aclifton/cpeg853-gem5,austinharris/gem5-riscv,SanchayanMaity/gem5,KuroeKurose/gem5,TUD-OS/gem5-dtu,aclifton/cpeg853-gem5,austinharris/gem5-riscv,Weil0ng/gem5,cancro7/gem5,rjschof/gem5,qizenguf/MLC-STT,TUD-OS/gem5-dtu,powerjg/gem5-ci-test,aclifton/cpeg853-gem5,briancoutinho0905/2dsampling,gedare/gem5,rjschof/gem5,markoshorro/gem5,Weil0ng/gem5,gedare/gem5,gem5/gem5,qizenguf/MLC-STT,HwisooSo/gemV-update,HwisooSo/gemV-update