dm: sata: Move ataid into struct ahci_uc_priv

This array relates to the AHCI controller so should be exist out on its
own in the file. Move it into the structure. Adjust functions that need
access to this to take the structure as a parameter.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>