Update Thread spec version to NOTICE file

Use correct version (1.1.1) of the Thread specification.

Author: Arto Kinnunen

NOTICE

@@ -1,17 +1,17 @@
 
-Nanostack contains an open source implementation of the Thread 1.0.1 Final Specification.
-The Thread 1.0.1 Final Specification is promulgated by the Thread Group. The Thread
+Nanostack contains an open source implementation of the Thread 1.1.1 Final Specification.
+The Thread 1.1.1 Final Specification is promulgated by the Thread Group. The Thread
 Group is a non-profit organization formed for the purposes of defining one or
 more specifications, best practices, reference architectures, implementation
 guidelines and certification programs to promote the availability of compliant
 implementations of the Thread protocol. Information on becoming a Member, including
 information about the benefits thereof, can be found at http://threadgroup.org.
 
 Nanostack is not affiliated with or endorsed by the Thread Group. Implementation
-of this Nanostack code does not assure compliance with the Thread 1.0.1 Final
+of this Nanostack code does not assure compliance with the Thread 1.1.1 Final
 Specification and does not convey the right to identify any final product as Thread
 certified. Members of the Thread Group may hold patents and other intellectual
-property rights relating to the Thread 1.0.1 Final Specification, ownership and
+property rights relating to the Thread 1.1.1 Final Specification, ownership and
 licenses of which are subject to the Thread Group’s IP Policies, and not this license.
 
 The included copyright to the Nanostack code is subject to the license defined in the