firmware: qcom_scm: Add support to assign multiple memory regions

The secure world allows for changing the ownership of multiple
(not necessarily physically contiguous) memory regions in one
secure call. Thus, expose an interface for clients to assign more
than one memory region per secure call.

Change-Id: Ic444627daee9d735b8b039ae3965e861cdcd110a
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>
Signed-off-by: Elliot Berman <eberman@codeaurora.org>