target-xtensa: implement info tlb monitor command

Command dumps valid ITLB and DTLB entries.

Signed-off-by: Max Filippov <[email protected]>
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 573b823..454d619 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1341,7 +1341,7 @@
 @item info pci
 show emulated PCI device info
 @item info tlb
-show virtual to physical memory mappings (i386, SH4, SPARC, and PPC only)
+show virtual to physical memory mappings (i386, SH4, SPARC, PPC, and Xtensa only)
 @item info mem
 show the active virtual memory mappings (i386 only)
 @item info jit