drivers: pci: imx: fix imx_pcie_remove function

drivers: pci: imx: fix imx_pcie_remove function

We have at least a minor count of boards, that failed to re-initialize
PCI express in the Linux kernel. Typical failure rate is 20% on affected
boards. This is mitigated by commit 6ecbe1375671 ("drivers: pci: imx:
add imx_pcie_remove function").

However, at least on some i.MX6 custom boards, when calling
assert_core_reset() as part of the first-time PCIe init, read access
to PCIE_PL_PFLR simply hangs. Surround this readl() with
imx_pcie_fix_dabt_handler() does not help. For this reason, the forced
LTSSM detection is only used on the second assert_core_reset() that is
called shorly before starting the Linux kernel.

Signed-off-by: Sven-Ola Tuecke <[email protected]>
Signed-off-by: Fabio Estevam <[email protected]>
Tested-by: David Müller <[email protected]>