coresight: cti: Correct checking return value of device resume

The return value of device resume function should be greater than
or equal to 0. Correct the conditional judgment to allow the return
value to be greater than 0. Otherwise, it can cause cti fail to
pass test sometimes.

Change-Id: I195b192d438b954c02c9d2cda2906075e8688ac9
Signed-off-by: Tao,Zhang <taozha@codeaurora.org>