mips: octeon: cpu.c: Enable AHCI/SATA support

mips: octeon: cpu.c: Enable AHCI/SATA support

For easy AHCI/ SATA integration, this patch adds board_ahci_enable()
for the MVEBU AHCI driver, which will be used by this platform. This
platform specific "enable" function will setup the proper endian
swapping in the AHCI controller so that it can be used by the common
AHCI code.

Additionally the endian swizzle entry for AHCI in
octeon_should_swizzle_table[] is removed, as this enabled the original
lowlevel code function, e.g. octeon_configure_qlm(), for the QLM setup
to work correctly.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Aaron Williams <awilliams@marvell.com>
Cc: Chandrakala Chavva <cchavva@marvell.com>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>