misc: sgi-gru: remove interrupt-context page-table walks

In the Linux kernel, the following vulnerability has been resolved: misc: sgi-gru: remove interrupt-context page-table walks The GRU TLB miss handler walks a process's page tables without holding page-table locks or a reference to the mapped page. It also uses a kernel page-table accessor on user page tables and supports only PMD-level large mappings on x86-64. Remove the direct walker. Send interrupt faults directly to user polling mode so the existing call-OS fallback retries them in process context. Remove the mmap-lock failure statistic that can no longer be incremented.