Documentation/sysrq.txt: Mention MIPS TLB dump (x)
Documentation/sysrq.txt: Mention MIPS TLB dump (x)

Commit d1e9a4f54735 ("MIPS: Add SysRq operation to dump TLBs on all
CPUs") added the 'x' sysrq key for dumping MIPS TLB entries, but didn't
document it in Documentation/sysrq.txt.

Add mention of the MIPS use of the 'x' SysRq key.

Reported-by: Maciej W. Rozycki <78f3a3d9d6e4d907a7d12e475d0a751d6b7e256b@linux-mips.org>
Signed-off-by: James Hogan <547fa85bb3888a0222eed8ec39e36708605c6d53@imgtec.com>
Acked-by: Jonathan Corbet <b2ce64d5587c02f12e367eac59751145a0660c51@lwn.net>
Cc: Maciej W. Rozycki <78f3a3d9d6e4d907a7d12e475d0a751d6b7e256b@linux-mips.org>
Cc: 562397917b9a8bf316569a848858b12fb417723f@linux-mips.org
Cc: 720929ea79be81617af4e0222565cf72ea2ee041@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/10720/
Signed-off-by: Ralf Baechle <92f48d309cda194c8eda36aa8f9ae28c488fa208@linux-mips.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs