ata: libahci_platform: support non-consecutive port numbers

So far ahci_platform relied on number of child nodes in firmware to
allocate arrays and expected port numbers to start from 0 without holes.
This number of ports is then set in private structure for use when
configuring phys and regulators.

Some platforms may not use every port of an ahci controller.
E.g. SolidRUN CN9130 Clearfog uses only port 1 but not port 0, leading
to the following errors during boot:
[    1.719476] ahci f2540000.sata: invalid port number 1
[    1.724562] ahci f2540000.sata: No port enabled

Update all accessesors of ahci_host_priv phys and target_pwrs arrays to
support holes. Access is gated by hpriv->mask_port_map which has a bit
set for each enabled port.

Update ahci_platform_get_resources to ignore holes in the port numbers
and enable ports defined in firmware by their reg property only.

When firmware does not define children it is assumed that there is
exactly one port, using index 0.

Signed-off-by: Josua Mayer <josua@solid-run.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>