ahci: add PCI bindings for Marvell 88SE6121/45 SATA controllers

Add AHCI PCI bindings for Marvell 88SE6121/45 SATA controllers.

The 88SE6121 controller is used, for example, in the Seagate Blackarmor NAS440 or the Iomega ix4-200d NAS.

As Pali Rohár explained [1], these controllers do not match the standard AHCI class code and therefore require an explizit PCI binding. The Linux kernel also uses this approach [2].

[1] https://lists.denx.de/pipermail/u-boot/2022-March/479197.html
[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/ata/ahci.c?h=v5.17#n557



Signed-off-by: Hajo Noerenberg <hajo-uboot@noerenberg.de>
Reviewed-by: Pali Rohár <pali@kernel.org>