PCI: Explicitly include correct DT includes

PCI: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.  As
part of that merge prepping Arm DT support 13 years ago, they "temporarily"
include each other. They also include platform_device.h and of.h. As a
result, there's a pretty much random mix of those include files used
throughout the tree. In order to detangle these headers and replace the
implicit includes with struct declarations, users need to explicitly
include the correct includes.

Link: https://lore.kernel.org/r/20230714174827.4061572-1-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>