gen_defines: generate ranges defines for PCIe I/O and memory regions

As described in IEEE Std 1275-1994, the PCIe bindings uses the ranges
property to describe the PCI I/O and memory regions.

Write _RANGES_ defines that will be used to determines the I/O and
memory regions from PCIe Controller drivers.

Also exclude "ranges" & "dma-ranges" property's length generation
alogn "reg" and "interrupt".

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>