power: smb1381: Fix NULL pointer dereference for audio adapter

In Type-C audio apapter removal case, a delay is configured to allow
audio driver to lower its enable gpio. The pointer to delay value is
not initialized for smb138x drivers.

Add default value of audio driver delay.

Change-Id: I2e89c00e7dec32ae13c90a4895f669bb20d48a3e
Signed-off-by: Umang Agrawal <uagrawal@codeaurora.org>