[PATCH v5 1/4] PCI: layerscape: Add function pointer for exit_from_l2()

[Roy Zang]

> From: Frank Li <frank.li at nxp.com>
> Subject: [PATCH v5 1/4] PCI: layerscape: Add function pointer for exit_from_l2()
> 
> Since difference SoCs require different sequence for exiting L2, let's add a
> separate "exit_from_l2()" callback. This callback can be used to execute SoC
> specific sequence.
> 
> Change ls_pcie_exit_from_l2() return value from void to int. Return error if
> exit_from_l2() failure at exit resume flow.
> 
> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>
> Signed-off-by: Frank Li <Frank.Li at nxp.com>
Acked-by:  Roy Zang <Roy.Zang at nxp.com>
Roy