dsp: afe: change lock sequence to avoid deadlock

Lock sequence for afe_alloc_cal does not comply with others. To
avoid deadlock, move afe_cmd_lock to the top caller in AFE.

Change-Id: I4ce03034c642c8b5e7e9e5e2ff4c73644980484b
Signed-off-by: Xiaojun Sang <xsang@codeaurora.org>