[POWERPC] Abolish PHYS_FMT macro from arch/powerpc

[POWERPC] Abolish PHYS_FMT macro from arch/powerpc

32-bit powerpc systems define a macro, PHYS_FMT, giving a printf
format string fragment for displaying physical addresses, since most
32-bit powerpc platforms use 32-bit physical addresses but a few use
64-bit physical addresses.

This macro is used in exactly one place, a rare error message, where
we can solve the problem more simply by just unconditionally casting
the address up to 64-bit quantity before formatting it.

This patch does so, meaning that as we bring MMU definitions from
asm-ppc over to asm-powerpc, cleaning them up in the process, we don't
need to implement this ugly macro (which additionally has a very bad
name for something global).

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>