ata: libata-transport: use static struct ata_transport_internal to simplify match...

ata: libata-transport: use static struct ata_transport_internal to simplify match functions

Both matching functions can make use of static struct
ata_transport_internal. This eliminates the dependency on static
variable ata_scsi_transport_template, and it allows to remove helper
to_ata_internal(). Small drawback is that a forward declaration of
both functions is needed.

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Niklas Cassel <cassel@kernel.org>