Validate Recording

Use the commands below to validate the recording function.

To record a 10-second sound track in the sample rate of 16 KHz:
```
# arecord -Dhw:0,0 -f S32_LE -r16000 -c2 -d 10 -t wav sound_32b_16k.wav
```
To record a 10-second sound track in the sample rate of 44.1 KHz:
```
# arecord -Dhw:0,0 -f S32_LE -r44100 -c2 -d 10 -t wav sound_32b_44100.wav
```