powerpc/p5040ds: add per pci endpoint liodn offset list

powerpc/p5040ds: add per pci endpoint liodn offset list

Add a new device tree property named "fsl,liodn-offset-list"
holding a list of per pci endpoint permitted liodn offsets.
This property is useful in virtualization scenarios
that implement per pci endpoint partitioning.
The final liodn of a partitioned pci endpoint is
calculated by the hardware, by adding these offsets
to pci controller's base liodn, stored in the
"fsl,liodn" property of its node.
The liodn offsets are interleaved to get better cache
utilization. As an example, given 3 pci controllers,
the following liodns are generated for the pci endpoints:
    pci0: 193 256 259 262 265 268 271 274 277
    pci1: 194 257 260 263 266 269 272 275 278
    pci2: 195 258 261 264 267 270 273 276 279

Signed-off-by: Laurentiu Tudor <Laurentiu.Tudor@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>