powerpc/eeh: Cleanup function names in EEH aux components

The patch does some cleanup on the function names of EEH
aux components. Currently, only couple of function names from
eeh_cache have been adjusted so that:

        * The function name has prefix "eeh_addr_cache".
        * Move around pci_addr_cache_build() in the header file
          to reflect function call sequence.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>