According to pci ids database that device id “abcd” for that given device is wrong because the BIOS has not been initialized it properly:
https://pci-ids.ucw.cz/read/PC/168c/abcd
The chip itself is AR9388-AL 1A:
It is supposed to be supported by the latest ROS releases (http://forum.mikrotik.com/t/rb-912uag-impossible-to-use-both-cards-irq-conflict/69890/15), but apparently not at all.