CVE-2026-89489 openrisc: fix arbitrary kernel memory access via or1k_atomic syscall

In the Linux kernel, the following vulnerability has been resolved: openrisc: fix arbitrary kernel memory access via or1katomic syscall sysor1katomic syscall 244 in the "or1k" ABI takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0r4 l.lwz...