Update arm64fx MEM groups bandwidth metrics

Created by: breiters

Metrics and correction terms taken from the fujitsu a64fx microarchitectural manual v1.4 page 85 and the a64fx pmu events errata v1.0.

L2D_CACHE_REFILL (corrected) = L2D_CACHE_REFILL - L2D_SWAP_DM - L2D_CACHE_MIBMCH_PRF
Bandwidth (corrected) = (L2D_CACHE_REFILL - (L2D_SWAP_DM + L2D_CACHE_MIBMCH_PRF) + L2D_CACHE_WB) * 256 / time

• https://github.com/fujitsu/A64FX/blob/master/doc/A64FX_Microarchitecture_Manual_en_1.4.pdf
• https://github.com/fujitsu/A64FX/blob/master/doc/A64FX_PMU_Events_Errata_1.0.pdf