ecppll: Fix help text

Signed-off-by: David Shah <dave@ds0.me>

libtrellis/tools/ecppll.cpp

diff --git a/libtrellis/tools/ecppll.cpp b/libtrellis/tools/ecppll.cpp
index 84e0a00..967e10f 100644
--- a/libtrellis/tools/ecppll.cpp
+++ b/libtrellis/tools/ecppll.cpp
@@ -104,7 +104,9 @@
 
   if(vm.count("help")){
     cerr << "Project Trellis - Open Source Tools for ECP5 FPGAs" << endl;
-    cerr << "ecpunpack: ECP5 bitstream to text config converter" << endl;
+    cerr << "ecppll: ECP5 PLL Configuration Calculator" << endl;
+    cerr << endl;
+    cerr << "This tool is experimental! Use at your own risk!" << endl;
     cerr << endl;
     cerr << "Copyright (C) 2018 David Shah <david@symbioticeda.com>" << endl;
     cerr << endl;