tee: amdtee: Add return_origin to 'struct tee_cmd_load_ta'

After TEE has completed processing of TEE_CMD_ID_LOAD_TA, set proper
value in 'return_origin' argument passed by open_session() call. To do
so, add 'return_origin' field to the structure tee_cmd_load_ta. The
Trusted OS shall update return_origin as part of TEE processing.

This change to 'struct tee_cmd_load_ta' interface requires a similar update
in AMD-TEE Trusted OS's TEE_CMD_ID_LOAD_TA interface.

This patch has been verified on Phoenix Birman setup. On older APUs,
return_origin value will be 0.

Cc: stable@vger.kernel.org
Fixes: 757cc3e9

 ("tee: add AMD-TEE driver")
Tested-by: Sourabh Das <sourabh.das@amd.com>
Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Acked-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>