LibVA Protected Content API

The Protected content APIs provide a generic mechanism for protected session
management with various assets in system such as Trusted Execution
Environment(TEE), GPU, Display. The protected session management includes
create, destroy, attach/detach, and execute according to contract with TEE,
GPU, and Display. The behavior of protected session APIs depend on
parameterization/configuration of protected sessions according to usage cases
such as TEE Communication Tools, Hardware Digital Rights Management(HWDRM) etc.

The Protected Content APIs play following roles - In TEE Communication Tools,
the APIs manifest as TEE client to honor TEE contract; In HWDRM, APIs manifest
as TEE/GPU/Display client to honor HWDRM contract.

The Protected Content APIs execute following workloads - In TEE Communication
Tools, the APIs provide infrastructure to execute TEE workloads such as TEE
capability discovery, versioning, provisioning etc.; In HWDRM, the APIs provide
infrastructure to execute HWDRM playback workloads such as license acquisition,
HW acceleration e.g. decryption/decoding of protected video/audio contents,
protected content display etc.

Signed-off-by: Gaurav Kumar <kumar.gaurav@intel.com>
Signed-off-by: Ryan T Huang <ryan.t.huang@intel.com>