coco: guest: arm64: Add support for guest initiated TDI bind/unbind

Add RHI for VDEV_SET_TDI_STATE

Note: This is not part of RHI spec. This is a POC implementation
and will be later switced to correct interface defined by RHI.

Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>