soc: qcom: Add ODL support for qdss bridge driver

Add ODL(On Device Logging) mode that it can read messages
from the mhi bus channel to user space via a device node
in qdss bridge driver.

Change-Id: I9d8f420ba8047adb4f27a284c6388faf899eada2
Signed-off-by: Shaoqing Liu <shaoqingliu@codeaurora.org>