EDAC/amd64: Remove unused register accesses

A number of UMC registers are read only for the purpose of debug printing. They
are not used in any calculations. Nor do they have any specific debug value.

Remove them.

Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20240606-fix-smn-bad-read-v4-1-ffde21931c3f@amd.com