ASoC: amd: Reporting accurate hw_ptr for acp3x dma

acp3x dma pointer callback has issues in reporting hw_ptr.
Modified logic to use linear position registers to
retrieve accurate hw_ptr.

Signed-off-by: Ravulapati Vishnu vardhan rao <Vishnuvardhanrao.Ravulapati@amd.com>
Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
Signed-off-by: Mark Brown <broonie@kernel.org>