[OpenBIOS] [RFC] Switch OFMEM to use phys_addr_t for physical addresses

[Mark Cave-Ayland]

Hi all,

Here is my first attempt at switching over OFMEM to use phys_addr_t for 
physical addresses. It was mainly a case of going through all of the 
OFMEM APIs by hand and then updating the definitions used to hold 
physical addresses, along with swapping over range_t to use phys_addr_t 
on the assumption that sizeof(phys_addr_t) >= sizeof(ucell).

Andreas - note I've not touched anything in ppc64 as I figure this is 
still experimental and I don't really have anything to test it with.

This patch seems to work on my SPARC64/PPC tests here, but since it 
touches a core part of OpenBIOS I'd like to get a little more feedback 
before committing it.

ATB,

Mark.