PCI: imx6: Fix spelling mistake: "contol" -> "control"

Trivial fix to spelling mistake in dev_err message

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Richard Zhu <hongxing.Zhu@nxp.com>