Rename imx6_pcie_start_link() to imx6_pcie_establish_link() to follow the
convention of other DesignWare-based host drivers.  No functional change.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NPratyush Anand <pratyush.anand@gmail.com>