MIPS: Octeon: cavium_octeon_defconfig: Enable OCTEON SATA

Commit a2127e40

 ("libata: support AHCI on OCTEON platform") added a
driver for the OCTEON AHCI controller. Enable this driver in the OCTEON
defconfig.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13816/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>