firmware: arm_ffa: Upgrade the driver version to v1.1

With quite a few v1.1 features supported, we can bump the driver version
to v1.1 now.

Link: https://lore.kernel.org/r/20231005-ffa_v1-1_notif-v4-17-cddd3237809c@arm.com


Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>