test: Add test for PCI device without compat string and with DT node

Add test which checks if a PCI device described in DT with an
entry and reg = <...> property, but without compatible string
results in a valid U-Boot PCI udevice with the udevice.node
populated with reference to this DT node. Also check if the
other PCI device without a DT node does not contain any bogus
udevice.node.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Tom Rini <trini@konsulko.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>