LibBSD - bus space support for PC PCI devices

[Chris Johns]

Hello,

These patches address 2 issues, PC PCI suport for non-Intel targets
and tests with static IP addresses faiing.

- PC PCI

BSPs like MVME2700 (MVME2307) have PC PCI devices with separate IO and
memory bus spaces mapped into separate address spaces. This requires
the BSP provides suitable remapping support. The PCI devices report relative
offsets and not absolute mappings. The support added is only enabled if
the BSP does this otherwise there is no change to existing BSPs and the
direct mappings the bus space support provides.

The bus space support has been cleaned up and a number of issues in some
of the support functions fixed. They must have not been used.

- Tests Waiting for Link UP

Tests that use the network test configured interface and have a static IP 
address did not wait for the link to be UP before starting the test. A DHCP 
client configuration would and simulators like QEMU did not simulate the 
time a PHY takes to come on line.

Add support to check if an interface has a valid and UP media link and
have tests wait for this to happen. I have added the support to 2 tests
and I am sure there other so please add the support when you find one.

Thanks
Chris