ath: fix coding style/readability in ath/ar9170

This is a patch to files in ath/ar9170 that fixes a set of warnings
found by checkpatch.pl tool. A line over 80 characters, a few empty
spaces before tab and a few empty characters before a new line.

Signed-off-by: Luis de Bethencourt <luisbg@ubuntu.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>