powerpc: Consolidate variants of real-mode MMIOs

We have all sort of variants of MMIO accessors for the real mode
instructions. This creates a clean set of accessors based on
Linux normal naming conventions, replacing all occurrences of
the old ones in the tree.

I have purposefully removed the "out/in" variants in favor of
only including __raw variants. Any code using these is already
pretty much hand tuned to operate in a very specific environment.
I've fixed up the 2 users (only one of them actually needed
a barrier in the first place).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/powernv/rng.c

@@ -62,7 +62,7 @@ int powernv_get_random_real_mode(unsigned long *v)
 
 	rng = raw_cpu_read(powernv_rng);
 
-	*v = rng_whiten(rng, in_rm64(rng->regs_real));
+	*v = rng_whiten(rng, __raw_rm_readq(rng->regs_real));
 
 	return 1;
 }