sata: dwc_ahsata: Fix incorrect free

Fix coverity issue CID 43665: Free of address-of expression (BAD_FREE)
incorrect_free: free frees incorrect pointer pp.

pp points the port array field of struct ahci_uc_priv, should not free it.

Acked-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Ye Li <ye.li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Simon Glass <sjg@chromium.org>