ARM: berlin: Enable SATA on Sony NSZ-GS7

Marvell Berlin BG2 based Sony NSZ-GS7 has an unpopulated SATA plug
on its PCB solder side. As it is quite easy to populate and I have
done it, enable AHCI and SATA by default.

Acked-by: Antoine Ténart <antoine.tenart@free-electrons.com>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>