CVE-2026-80747: drm/amdkfd: Add bounds check for CRAT subtype length

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: Add bounds check for CRAT subtype length The CRAT parser validates that the subtype header fits within the image, but does not verify that the advertised subtype length fits. A malformed CRAT table with an oversized length field causes out-of-bounds reads when kfd_parse_subtype() casts the header to specific subtype structures. Add validation that sub_type_hdr + length does not exceed the image boundary before parsing the subtype contents. (cherry picked from commit 48e1d1e6e8798aef0312e68d8e586021b5b3cf4d)