powerpc: pci-ioda: Use a single function to emit logging messages

No need for 3 functions when a single one will do.

Modify the function declaring macros to call the single function.

Reduces object code size a little:

$ size arch/powerpc/platforms/powernv/pci-ioda.o*
   text	   data	    bss	    dec	    hex	filename
  22303	   1073	   6680	  30056	   7568	arch/powerpc/platforms/powernv/pci-ioda.o.new
  22840	   1121	   6776	  30737	   7811	arch/powerpc/platforms/powernv/pci-ioda.o.old

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>