ext: lib: tinycbor: Add tinyCBOR as an ext lib

The TinyCBOR library is a small Concise Binary Object
Representation (CBOR) encoder and decoder library, optimized for
very fast operation with very small footprint.

Origin: TinyCBOR
License: MIT
URL: https://github.com/intel/tinycbor


Version: 0.5.0-beta1
commit: 497066ee87dd54341adaa1195bf15ad11ee33b20
Purpose: Introduction of TinyCBOR
Maintained-by: External

Signed-off-by: Vipul Rahane <vipulrahane@apache.org>