msm:audio: qdsp5: Handle EOS buffer after audio flush

EOS buffer is not getting processed in following scenario is
encountered:
-Driver Recieves FLUSH command from apps
-Application sends EOS buffer to the driver after flush
command has completed
-NEEDS_DATA messages from DSP is Recieved by driver

In above scenario driver blocks for forever in write wait queue
and EOS buffer never gets processed.

Fix this by sending wakeup when NEEDS_DATA message is received.

CRs-Fixed: 292954, 293145
Signed-off-by: Manish Dewangan <manish@codeaurora.org>
(cherry picked from commit c729e63)

Change-Id: Iba4f7850e546d3816c31389a33984af28cca6503
Signed-off-by: Sunil Joseph <sunilj@codeaurora.org>