relate perlib to the libs/ directory

perflib was made before we had libs, so put it into its new, proper
home.

Cargo.toml

@@ -95,10 +95,10 @@ members = [
   #"services/test-spawn/spawn",
   "services/usb-test",
   "services/usb-device-xous",
-  "tools/perflib",
   "kernel",
   "loader",
   "libs/chat",
+  "libs/perflib",
   "libs/userprefs",
   "libs/tls",
   "libs/xous-pio",

apps/vault/Cargo.toml

@@ -59,7 +59,7 @@ net = { path = "../../services/net" }
 com_rs = { git = "https://github.com/betrusted-io/com_rs", rev = "891bdd3ca8e41f81510d112483e178aea3e3a921" }
 
 # performance profiling
-perflib = { path = "../../tools/perflib", optional = true }
+perflib = { path = "../../libs/perflib", optional = true }
 utralib = { version = "0.1.24", optional = true, default-features = false }
 
 # testing

services/pddb/Cargo.toml

@@ -52,7 +52,7 @@ modals = { path = "../modals" }
 utralib = { version = "0.1.24", optional = true, default-features = false }
 
 # performance profiling
-perflib = { path = "../../tools/perflib", optional = true }
+perflib = { path = "../../libs/perflib", optional = true }
 
 [target.'cfg(any(windows,unix))'.dependencies]
 rand = "0.8.5"

services/shellchat/Cargo.toml

@@ -90,7 +90,7 @@ ring = { version = "0.16.20", optional = true }
 tungstenite = { version = "0.20.0", optional = true }
 
 # for performance testing
-perflib = { path = "../../tools/perflib", optional = true }
+perflib = { path = "../../libs/perflib", optional = true }
 random-pick = { version = "1.2.15", optional = true }
 
 # for the curve25519 tests