ts-kernel-build: add kernel kconfig for the Arndale

ts-kernel-build: add kernel kconfig for the Arndale

The Linux commit 33629d35090f5ce2b1b4ce78aa39954c603536d5 has
removed the 'snps,dwc-ahci' compatible from the generic
AHCI-platform driver control module selected by
CONFIG_SATA_AHCI_PLATFORM.

A new driver, the DWC AHCI SATA platform driver is now implemented
and handles the above compatible when CONFIG_AHCI_DWC is selected.

The module is needed for the Arndale board to have the SATA controller
working, so enable the CONFIG_AHCI_DWC as additional kconfig parameter
in ts-kernel-build.

Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>