ARM: dts: berlin: enable the eSATA interface on the BG2Q DMP

The BG2Q has an AHCI SATA controller with an eSATA interface. Enable it.
Only enable the first port, the BG2Q DMP does not support the second one.

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