target-arm: Reindent ancient page-table-walk code

target-arm: Reindent ancient page-table-walk code

A few of the oldest parts of the page-table-walk code have broken indent
(either hardcoded tabs or two-spaces). Reindent these sections.

For ease of review, this patch does not touch the brace style and
so is a whitespace-only change.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Greg Bellows <greg.bellows@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>