dsp: Synchronize afe apr send pkt commands

Synchronize afe apr send pkt commands to avoid the state
variable modification for multiple commands sent in
parallel. Use the common interface afe_apr_send_pkt
to send the apr pkt.

Change-Id: I17a573a28e227cce882c3330887ae2756ca4addb
Signed-off-by: Aditya Bavanari <abavanar@codeaurora.org>