edac: ibecc: Add support for EHL SKU13, SKU14, SKU15

Add support for missing EHL SKUs. The information about SKUs is
already public and available in Linux kernel:
https://github.com/torvalds/linux/blob/


38f80f42147ff658aff218edb0a88c37e58bf44f/drivers/edac/
igen6_edac.c#L197-L208

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
(cherry picked from commit f6069aa8)