firmware: arm_ffa: Setup the partitions after the notification initialisation

firmware: arm_ffa: Setup the partitions after the notification initialisation

Currently the notifications are setup of the partitions are probed and
FF-A devices are added on the FF-A bus. The FF-A driver probe can be
called even before the FF-A notification setup happens which is wrong
and may result in failure or misbehaviour in the FF-A partition device
probe.

In order to ensure the FF-A notifications are setup before the FF-A
devices are probed, let us move the FF-A partition setup after the
completion of FF-A notification setup.

Link: https://lore.kernel.org/r/20231024-ffa-notification-fixes-v1-2-d552c0ec260d@arm.com
Tested-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>