soc: qcom: spcom: propagate response timeout error

HLOS client send request to SP server and expect response within timeout.
if timeout expires, return ETIMEDOUT error, rather than a general error.

Change-Id: Ic7691848ff133196bf31294c010e98846de2c470
Signed-off-by: Amir Samuelov <amirs@codeaurora.org>