drm/amdgpu: Add RAS EEPROM table.

Add RAS EEPROM table manager to eanble RAS errors to be stored
upon appearance and retrived on driver load.

v2: Fix some prints.

v3:
Fix checksum calculation.
Make table record and header structs packed to do correct byte value sum.
Fix record crossing EEPROM page boundry.

v4:
Fix byte sum val calculation for record - look at sizeof(record).
Fix some style comments.

v5: Add description to EEPROM_TABLE_RECORD_SIZE and syntax fixes.

Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Luben Tuikov <Luben.Tuikov@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>