dsp: msm_audio_ion: check only for probe complete for ION alloc

While allocating and importing ION buffers, make sure to check
for probe complete flag before proceeding instead of checking for
the flag AND smmu_enabled flag. This way the restriction will be
centralized for either types of targets with and without SMMU.

Change-Id: I558e19724d1002a602377a636e274bc90ca8262d
Signed-off-by: Banajit Goswami <bgoswami@codeaurora.org>