powerpc: Add more PPC bit conversion macros

powerpc: Add more PPC bit conversion macros

BugLink: http://bugs.launchpad.net/bugs/1691973
Add 32 and 8 bit variants

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
(cherry picked from commit 22bd64a621cc80beeb009abec3d3df98ec0131c5)
Signed-off-by: Gustavo Walbon <gwalbon@linux.vnet.ibm.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>