meta-ampere: mtjade: enable IPMI SSIF

Enable IPMI SSIF support for Mt.Jade platform. This also supports to set
BMC_OK GPIO when SSIF service starts and unset when SSIF service stops.

Tested:
1. Check if ssifbridge.service service starts
root@mtjade:~# systemctl status ssifbridge.service  | grep Active
     Active: active (running) since Tue 2022-10-11 02:17:55 UTC; 1h 49min ago
2. From Host OS, check if IPMI SSIF works.

Signed-off-by: Thang Q. Nguyen <thang@os.amperecomputing.com>
Change-Id: I6b3a764f15c63b45acafdb590c7dfb223bfdd3a3