drm/amdgpu: Add support for RAS table at 0x40000

Add support for RAS table at I2C EEPROM address of 0x40000, since on some
ASICs it is not at 0, but at 0x40000.

Cc: Alex Deucher <Alexander.Deucher@amd.com>
Cc: Kent Russell <kent.russell@amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Tested-by: Kent Russell <kent.russell@amd.com>
Reviewed-by: Kent Russell <kent.russell@amd.com>
Reviewed-by: Alex Deucher <Alexander.Deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>