Set the DEVICE_ID of i.MX8 PCIe and add i.MX8 PCIE EP device support in
pci_endpoint_test driver.

Link: https://lore.kernel.org/r/1673847684-31893-11-git-send-email-hongxing.zhu@nxp.comSigned-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>