Use 'scaling_max_freq' when 'scaling_available_frequencies' is not available.

In recently arm images, there is no such
'scaling_available_frequencies' file, which leads failure of
crosperf. Fixed this by choosing 'scaling_max_freq'.

TEST=tested on daisy
BUG=None

Change-Id: I433e161495421c57854234fd0e7f7e54406bb9e8
Reviewed-on: https://chrome-internal-review.googlesource.com/154579
Reviewed-by: Caroline Tice <cmtice@google.com>
Commit-Queue: Han Shen <shenhan@google.com>
Tested-by: Han Shen <shenhan@google.com>
1 file changed