ASoC: msm: qdsp6: Fix q6asm_memory_unmap issue

In q6asm_audio_client_buf_free_contiguous() function q6asm_memory_unmap
is called with wrong parameter. q6asm_memory_unmap() expects physical
address, but size of the buffer is passed as argument, hence
q6asm_memory_unmap returned with error code 2. Fix this issue by
passing physical address.

CRs-fixed: 296210
Signed-off-by: Deepa Madiregama <dmadireg@codeaurora.org>