EDAC, MCE, AMD: Add an MCE signature for new Fam15h models

Add a new error signature for Family 15h, models 30h-3fh. Patch has been
tested on Fam15h using mce_amd_inj facility and has been verified to
work correctly.

Signed-off-by: Aravind Gopalakrishnan <aravind.gopalakrishnan@amd.com>
 [ cleanup commit message and error string ]
Signed-off-by: Borislav Petkov <bp@suse.de>