qseecom: Check if app exists before loading the app

There is a chance of send a request to QSEE to load an app that
is already previously loaded. Requesting QSEE to load an app
that is already loaded will result in a failure.

Issuing a request to QSEE to check if app already exists before
issuing a request to load it, all within the same app_access_lock
mutex, fixes this issue.

CRs-Fixed: 420473
Change-Id: Ie839db89a10644d4f1d84ffa3a87cea8da16e796
Signed-off-by: Mona Hossain <mhossain@codeaurora.org>
1 file changed