misc: fastrpc: Pass proper arguments to scm call

For CMA memory allocation, ownership is assigned to DSP to make it
accessible by the PD running on the DSP. With current implementation
HLOS VM is stored in the channel structure during rpmsg_probe and
this VM is passed to qcom_scm call as the source VM.

The qcom_scm call will overwrite the passed source VM with the next
VM which would cause a problem in case the scm call is again needed.
Adding a local copy of source VM whereever scm call is made to avoid
this problem.

Fixes: 08715610

 ("misc: fastrpc: Add support for audiopd")
Cc: stable <stable@kernel.org>
Signed-off-by: Ekansh Gupta <quic_ekangupt@quicinc.com>
Reviewed-by: Elliot Berman <quic_eberman@quicinc.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20240224114247.85953-2-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>