Revert r220427, "[Hexagon] Adding encoding bits for add opcode."

It brought cyclic dependecy between HexagonAsmPrinter and HexagonDesc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220478 91177308-0d34-0410-b5e6-96231b3b80d8
[CMake] Prune trailing whitespace.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220479 91177308-0d34-0410-b5e6-96231b3b80d8