qseecom: Add support to handle multiple app load & unload

Media server is associated with multiple apps on TZ-side.
Unloading a single app for clean up is not enought. QSEECOM
needs to handle the app load & unload of multiple apps
associated with the client. During app_load & app_unload
along with app_id, app_name should also be checked. Besides,
keymaster will not be unloaded and app search execution
during app unload is optimized.

Change-Id: Ie92e97b9154851b713a8c3394b8ed10fdbdebd2f
Signed-off-by: Zhen Kong <zkong@codeaurora.org>
Signed-off-by: William Clark <wclark@codeaurora.org>