soc: qcom: hab: add error handling when dt item is missing

If certain testgipc node under aliases in device tree is
missing, ep_path remains NULL and it will cause NULL
dereference problem later in the code. We need to go to
error handler and deinitialize everything under this
condition.

Change-Id: Ib687390402a6210b63fe2a39500b3216c2ae21e3
Signed-off-by: Jiacheng Zheng <jiaczhen@codeaurora.org>