Update README.md
Updated for Bolt 1.2
Checkin for Bolt 1.2 GA release.
New features added:
-Function parity between AMP and OpenCL Backends.
-Transform iterator support in OpenCL backend.
-Permutation iterator support in AMP backend.
-Performance optimizations.
updated link to tbb documentation
Merge pull request #1 from HSA-Libraries/master

update my fork to master