CHROMIUM: ALSA: hda/ca0132 - Fix divide error when frame_bits not set

CHROMIUM: ALSA: hda/ca0132 - Fix divide error when frame_bits not set

When frame_bits hasn't been set in snd_pcm_runtime, skip the calcuation
for latency value.

BUG=chrome-os-partner:12926
TEST=Manual. Boot system on battery, open youtube can play without
crash. Run looptest tool with debug log can see latency value changes
correctly according to effects setting.

Change-Id: Iab2d289d9f33e5d4ed178764217b1a08c30c73c5
Signed-off-by: Hsin-Yu Chao <hychao@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/36047
Reviewed-by: Chih-Chung Chang <chihchung@chromium.org>
Commit-Ready: Dylan Reid <dgreid@chromium.org>
Reviewed-by: Dylan Reid <dgreid@chromium.org>
Tested-by: Dylan Reid <dgreid@chromium.org>