rtas: Improve rtas-do-config-@ and rtas-do-config-! a little bit
rtas: Improve rtas-do-config-@ and rtas-do-config-! a little bit

As soon as we are booting with at least one PCI device, the
rtas-do-config-@ Forth word is called quite often, so it
makes sense that we look up the corresponding RTAS token
only once instead of each time the function is called.
Also the "ffffffff and" operation on the lower half of the
PUID is not really required and can be removed, since the
"l!" Forth word is storing the lower four bytes only anyway.

Signed-off-by: Thomas Huth <9e65be74847981e55b2564b6266c57d86d3bac05@redhat.com>
Signed-off-by: Alexey Kardashevskiy <ac1fc56530d7d037e1ea666f130daca22d72f964@ozlabs.ru>

open-power-host-os/slof,stefanberger/SLOF-tpm,aik/SLOF,open-power-host-os/slof,qemu/SLOF,qemu/SLOF,stefanberger/SLOF-tpm,qemu/SLOF,stefanberger/SLOF-tpm,open-power-host-os/slof,aik/SLOF,open-power-host-os/slof,aik/SLOF