firmware: coreboot: Validate table bounds

In the Linux kernel, the following vulnerability has been resolved: firmware: coreboot: Validate table bounds The existing coreboot_table_populate() bounds checks limit individual entries to the mapped length. However, coreboot_table_probe() replaces the platform resource length with header and table sizes supplied by firmware before mapping the full table. A malformed table can overflow the 32-bit size addition or advertise an extent beyond the resource, causing the driver to map and parse memory outside the resource. A resource shorter than the fixed header is also mapped as though it contained a complete header. Reject resources shorter than the fixed header. After validating the signature, require a complete header, calculate the advertised extent with overflow checking, and reject extents beyond the resource before remapping the table.