mem: Add initial HBM configurations

mem: Add initial HBM configurations

Created the following HBM configurations:
1) HBM gen1 (x128/CH), 2Gb die, 4H stack, 1Gbps, 8 channels
2) HBM gen2 (x64/PC), 8Gb die, 4H stack, 1Gbps, 16 pseudo-channels

The configuration values are based on:
- The HBM gen1 public JEDEC spec
- Publically released data from MemCon presentations
- Timing extrapolated from existing LPDDR configurations

Will adjust once specs become available.