Pull up following revision(s) (requested by bouyer in ticket #1040):
sys/arch/x86/include/bus.h: revision 1.18
sys/arch/x86/include/isa_machdep.h: revision 1.7
sys/arch/x86/x86/bus_space.c: revision 1.21
Apply patch proposed on port-amd64/port-i386, allowing to use a 64bit
bus_addr_t on i386PAE kernels:
change bus_addr_t to be a paddr_t (so its size follows paddr_t depending
  on options PAE)
remplace bus_addr_t with vaddr_t where the value is used as a virtual address.
Difference with the proposed patch: cast to uintmax_t and use %jx in
printf() as suggested by Joerg.

(snj)