Fix checkpatch.pl warnings and errors

  ERROR: code indent should use tabs where possible
  #45: FILE: pcm.h:41:
  +        snd_pcm_uframes_t period_off;^I/* current position in current period */$

  WARNING: please, no spaces at the start of a line
  #45: FILE: pcm.h:41:
  +        snd_pcm_uframes_t period_off;^I/* current position in current period */$

  total: 1 errors, 1 warnings, 67 lines checked

Signed-off-by: Antonio Ospite <ao2@amarulasolutions.com>
Remove empty lines at the end of the files

Done by .../linux/scripts/cleanfile

Signed-off-by: Antonio Ospite <ao2@amarulasolutions.com>