tests/tcg: make test-mmap a little less aggressive

tests/tcg: make test-mmap a little less aggressive

The check_aligned_anonymous_unfixed_mmaps and
check_aligned_anonymous_unfixed_colliding_mmaps do a lot of mmap's and
copying of data. This is especially unfriendly to targets like hexagon
which have quite large pages and need to do sanity checks on each
memory access.

While we are at it clean-up the white space and style issues from the
legacy code. As we no longer do quite so much needless memory access
we can also remove the hexagon timeout hack.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <20210709143005.1554-27-alex.bennee@linaro.org>