SoC S6: mailbox: add aocpu alive detection and mailbox retry [1/4]

PD#SWPL-172976

Problem:
add aocpu alive detection and mailbox retry mechanism to
avoid mailbox message lost due to aocpu crash or mailbox
signal lost occasionally

Solution:
add aocpu alive detection and mailbox retry mechanism

Verify:
S6-BL201

Change-Id: I959211f603b38cb7e6d25ead165e974185b21d64
Signed-off-by: Yao Jie <jie.yao@amlogic.com>
6 files changed