dsp: msm_audio_ion: add ION support for targets without SMMU

ION memory allocator is used for audio use cases even on targets
without SMMU. Add support for ION on those targets where ADSP
might not have an SMMU in front of it.

Change-Id: Iaacbd66edb32c8ee7c14a5ab291abe54960725b8
Signed-off-by: Banajit Goswami <bgoswami@codeaurora.org>