UPSTREAM: firmware: arm_ffa: Add missing rwlock_init() in ffa_setup_partitions()

Add the missing rwlock initialization for the individual FF-A partition
information in ffa_setup_partitions().

Bug: 254441685
Fixes: 0184450b ("firmware: arm_ffa: Add schedule receiver callback mechanism")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20240108-ffa_fixes_6-8-v1-1-75bf7035bc50@arm.com


Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
(cherry picked from commit 59b2e242)
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: I3011ee8173bf26161bad6a1f302d7b61bd6a0d26