Adds a PCI device entry for Raven Ridge. Raven Ridge is an APU with a
dedicated AMD Secure Processor having Trusted Execution Environment (TEE)
support. The TEE provides a secure environment for running Trusted
Applications (TAs) which implement security-sensitive parts of a feature.

This patch configures AMD Secure Processor's TEE interface by initializing
a ring buffer (shared memory between Rich OS and Trusted OS) which can hold
multiple command buffer entries. The TEE interface is facilitated by a set
of CPU to PSP mailbox registers.

The next patch will address how commands are submitted to the ring buffer.

Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Co-developed-by: NDevaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: NDevaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: NRijo Thomas <Rijo-john.Thomas@amd.com>
Acked-by: NGary R Hook <gary.hook@amd.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>