optee: FF-A: dynamic protected memory allocation

optee: FF-A: dynamic protected memory allocation

Add support in the OP-TEE backend driver dynamic protected memory
allocation with FF-A.

The protected memory pools for dynamically allocated protected memory
are instantiated when requested by user-space. This instantiation can
fail if OP-TEE doesn't support the requested use-case of protected
memory.

Restricted memory pools based on a static carveout or dynamic allocation
can coexist for different use-cases. We use only dynamic allocation with
FF-A.

Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>