Introduce a "family flags" bitmask that can be used to indicate any
special behavior needed on a per-family basis.

Add a flag to indicate a system uses the new register offsets introduced
with Family 19h Model 10h.

Use this flag to account for register offset changes, a new bitfield
indicating DDR5 use on a memory controller, and to set the proper number
of chip select masks.

Rework f17_addr_mask_to_cs_size() to properly handle the change in chip
select masks. And update code comments to reflect the updated Chip
Select, DIMM, and Mask relationships.

[uninitialized variable warning]
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: William Roche <william.roche@oracle.com>
Link: https://lore.kernel.org/r/20220202144307.2678405-3-yazen.ghannam@amd.com