Bus: Make the default bus width 8 bytes instead of 64
Bus: Make the default bus width 8 bytes instead of 64

This patch changes the default bus width to a more sensible 8 bytes
(64 bits), which is in line with most on-chip buses. Although there
are cases where a wider or narrower bus is useful, the 8 bytes is a
good compromise to serve as the default.

This patch changes essentially all statistics, and will be bundled
with the outstanding changes to the bus.

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