So far NuttX has supported OP-TEE interfacing over
local and RPMsg sockets. This commit introduces support
for direct invocation of OP-TEE through arm SMCs. The
SMC transport is enabled through CONFIG_DEV_OPTEE_SMC.
This SMC implementation has been tested only with arm64,
OP-TEE rev 4.4.
Note that it does not support reverse direction RPCs,
i.e. from the Secure World to the Normal World to
something like optee supplicant. A basic RPC handling
skeleton is provided with implementation for some
basic functions (alloc/free mem, and foreign interrupts)
but no supplicant command handling.
(+one minor change s/parm/param in arch/arm64/include/syscall
to satisfy the spellchecker during PR)
Signed-off-by: George Poulios <gpoulios@census-labs.com>