firmware: arm_ffa: Make memory apis ffa_device independent

There is a requirement to make memory APIs independent of the ffa_device.
One of the use-case is to have a common memory driver that manages the
memory for all the ffa_devices. That common memory driver won't be a
ffa_driver or won't have any ffa_device associated with it. So having
these memory APIs accessible without a ffa_device is needed and should
be possible as most of these are handled by the partition manager(SPM
or hypervisor).

Drop the ffa_device argument to the memory APIs and make them ffa_device
independent.

Link: https://lore.kernel.org/r/20220907145240.1683088-7-sudeep.holla@arm.com


Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>