powerpc/powernv/pci: Rename TCE invalidation calls

The TCE invalidation functions are fairly implementation specific,
and while the IODA specs more/less describe the register, in practice
various implementation workarounds may be required. So name the
functions after the target PHB.

Note today and for the foreseeable future, there's a 1:1 relationship
between an IODA version and a PHB implementation. There exist another
variant of IODA1 (Torrent) but we never supported in with OPAL and
never will.

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