ata: ahci-dwc: Add platform-specific quirks support

Some DWC AHCI SATA IP-core derivatives require to perform small platform
or IP-core specific setups. They are too small to be placed in a dedicated
driver. It's just much easier to have a set of quirks for them right in
the DWC AHCI driver code. Since we are about to add such platform support,
as a pre-requisite we introduce a platform-data based DWC AHCI quirks API.
The platform data can be used to define the flags passed to the
ahci_platform_get_resources() method, additional AHCI host-flags and a set
of callbacks to initialize, re-initialize and clear the platform settings.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>