firmware: qcom_scm-64: Add SCM results to descriptor

Remove knowledge of arm_smccc_res struct from client wrappers so that
client wrappers only work QCOM SCM data structures. SCM calls may have
up to 3 arguments, so qcom_scm_call_smccc is responsible now for filling
those 3 arguments accordingly.

Change-Id: I9712f75f6bea0a6528ccd5a69bc1602493574e19
Signed-off-by: Elliot Berman <eberman@codeaurora.org>