msm: qdsp6v2: set device channels on vocproc

Media format data is used only to account for additional buffering
required in vocproc when a fractional sample rate is set. Set device
channels irrespective of the media format info in order to configure
the input no of channels when a custom topology is used.

CRs-Fixed: 1116092
Change-Id: I6eadba65dbed102aec085d99f28c39e66ea4b89b
Signed-off-by: Siena Richard <sienar@codeaurora.org>