soc: qcom: ssr: Add option to relax on ssr failures

SSR failures are considered fatal and results in system panic.
In certain scenarios system can continue to work even with a
failed subsystem.

Add an option in subsystem descriptor to relax on ssr failures.

Change-Id: I86dcaa615d6443937077880d9a91070d9c22ea1f
Signed-off-by: Arun KS <arunks@codeaurora.org>