audio: add readMmap and writeMmap for mmap stream.

Add readMmap and writeMmap for mmap stream to let the driver
know that the client has started data transfer.

Bug: 398760899
Test: atest VtsHalAudioCoreTargetTest
Change-Id: I6f8fb81b2866a703aebaf89a59d6bba96655b190
Signed-off-by: Aiguo <aiguo.feng@amlogic.corp-partner.google.com>
2 files changed