ata-6.1-rc2

Several minor fixes for rc2:

* Fix the module alias for the ahci_imx driver to get autoloading to
  work (from Alexander).

* Fix a potential array-index-out-of-bounds problem with the enclosure
  managment support in the ahci driver (from Kai-Heng).

* Several patches to fix compilation warnings thrown by clang in the
  ahci_st, sata_rcar, ahci_brcm, ahci_xgene, ahci_imx and ahci_qoriq
  drivers (from me).