qseecom: register bus bandwidth mode when loading app

When there are multiple running qseecom clients, ce clock may be disabled
by one client while TZ is still loading another client's app, which will
lead to load app failure. So, we make a change to register bus bandwidth
mode before loading app and avoid to disable clock when current bandwidth
mode is not INACTIVE.

Change-Id: I1727f6fc038baf95da39089e1f0faefe42f3d40c
Signed-off-by: Zhen Kong <zkong@codeaurora.org>