IVGCVSW-5585 Add LICENSE file to third-party/stb lib
IVGCVSW-5585 Add LICENSE file to third-party/stb lib

Change-Id: Ifacd03d322284df6a7fa9e4ce5121b16ae8bc99f
Signed-off-by: Jim Flynn <af5ec5733a77f43f3ed5c8afc85bbe49b9031cfd@arm.com>

ARM-software/armnn,ARM-software/armnn,ARM-software/armnn