When we determine from hardware what the size of IPA memory is
we compare it against what we learned about it from DT.

If DT defines a region that's larger than actual memory, we use the
smaller actual size and issue a warning.

If DT defines a smaller region than actual memory we issue a warning
too.  But in this case the difference is harmless; so rather than
issuing a warning, just provide a debug message instead.

Reorder these checks so the one that matters more is done first.

Reported-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>