ARM: tegra: enable PCIe in Jetson TK1 DT

Enable both PCIe ports, one of which is connected to an onboard ethernet
chip, whereas the other goes to a miniPCIe slot.

Signed-off-by: Thierry Reding <treding@nvidia.com>
[swarren, fixed PCIe supply property names in DT]
Signed-off-by: Stephen Warren <swarren@nvidia.com>