ipq40xx: do not remove pci@40000000 for ap.dk04.1

ipq40xx: do not remove pci@40000000 for ap.dk04.1

This pci@40000000 node from upstream was dropped when the device
was converted from local DTS(I) files to kernel patches in [1] to
ensure that change was purely cosmetic.

However, the DK04.1 has a PCI-E slot by default, so let's keep
(i.e. not remove) the kernel definition now.

[1] c4beac9ea2e1 ("ipq40xx: use upstream DTS files for IPQ4019/AP-DK04.1")

Suggested-by: Robert Marko <robert.marko@sartura.hr>
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>