[coreboot] Add memory support for mb/apple: MacBook Air 5,2 (A1466)

[Mariusz Grabarczyk]

Hi

I would like to have memory support added for mb/apple: MacBook Air 5,2 (A1466)
Per
https://review.coreboot.org/c/coreboot/+/32604/36/Documentation/mainboard/ap...

Originally
https://review.coreboot.org/c/coreboot/+/32604

If your RAM configuration is not supported, you can help supporting it. Run
`sudo inteltool -m`, save output to a text file and send a message to coreboot

inteltool -g | get_macbook_ramcfg -m mba52
unsupported memory configuration 1

inteltool -m >> macbook52_memory

Attached is dump file