ARM: imx: Call imx_pcie_remove() only for non-DM PCI driver

The DM iMX PCI driver has DM_FLAG_OS_PREPARE set and will call
imx_pcie_remove() from the .remove callback. Do not call it from
the architecture code again.

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>