audio: add enable count for PDM module [1/1]

PD#IPTV-3723

Problem:
One use case is PDM module is sendig data
to both PDM device and LOOPBACK device.
Close one will make another useless.

Solution:
Add management of the PDM module by
a enable count.

Verify:
SM1.

Change-Id: Iceeb756c02671b16dbc3c49a9b793a50e6e559b5
Signed-off-by: Shuai Li <shuai.li@amlogic.com>
1 file changed