SoC s6: bl30 support DSP suspend resume with ffv [1/2]

PD#SWPL-184689

Problem:
DSP needs to support low power mode with ffv.

Solution:
Add mbox callback for DSP to AOCPU.

Verify:
S6

Change-Id: I7cf18a6d6541af0fd1b523cc30012280062f50a1
Signed-off-by: bangzheng.liu <bangzheng.liu@amlogic.com>
3 files changed