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.

Change-Id: Iea53362a21e359e54e40a0a93688a05264cfde5c