arm64: defconfig: Add Juno SATA controller

The ARM Juno (r1 and r2) boards feature a SATA controller soldered
on the board and connected to the PCI bus.
Add the respective driver to defconfig to get hard disks supported out
of the box on the Junos.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>