uapi: sound: add bt external sink delay parameter

- Add support for reporting external sink delay
  for split a2dp usecase

- Add RUN_STARTIME_RUN_AT_ABSOLUTEIME run mode to
  support audio sync between bt and speaker in
  relay and grandpa mode

Change-Id: Ie7ff48f2e47fde93c4ed9e24fab024918772be82
Signed-off-by: Aishwarya Sharma <aisharma@codeaurora.org>