hal: Detect sound card dynamically

- HAL always assumed SOUND_CARD/MIXER_CARD
  number to be zero. This could cause HAL
  not to load when some other card is
  detected earlier to HAL.
- Fix by removing these Macro(s) and reading
  correct sound card number runtime while loading
- Corrected its use cases across HAL replacing it
  with appropriate platform API

CRs-fixed: 580226

Change-Id: I4512e4a2f7f81d8415c3ba8ec393c96867e6d69a