ata: Fix an instance of SPL_SATA_SUPPORT

The _SUPPORT suffix should be dropped. This happened because the rename
was applied around the same time as this new option, so did not include
renaming the new option.

The relevant commits are:

   f7560376 sata: Rename SATA_SUPPORT to SATA
   73059529 ata: ahci-pci: Add new option CONFIG_SPL_AHCI_PCI

Fix it.

Signed-off-by: Simon Glass <sjg@chromium.org>