pci: imx: Pass driver private data around

pci: imx: Pass driver private data around

Pass the driver private data around the driver as much as possible, instead
of having it as a static global variable. This is done in preparation for
the DM conversion, no functional change.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Stefano Babic <sbabic@denx.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
(cherry picked from commit d2cc2e86f8e12393f2adf47c9a8694475e92e05a)