tee: optee: Drop ffa_ops in optee_ffa structure using ffa_dev->ops directly

tee: optee: Drop ffa_ops in optee_ffa structure using ffa_dev->ops directly

Now that the ffa_device structure holds the pointer to ffa_dev_ops,
there is no need to obtain the same through ffa_dev_ops_get().

Just use the ffa_dev->ops directly. Since the ffa_device itself carries
ffa_dev_ops now, there is no need to keep a copy in optee_ffa structure.

Drop ffa_ops in the optee_ffa structure as it is not needed anymore.

Link: https://lore.kernel.org/r/20220907145240.1683088-3-sudeep.holla@arm.com
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>