[3/n] Internal 4GB allocator.

-Do not create allocator 32 bit with every DRM memory manager
-This is not needed for apps that do not use this.
-Add allocation of allocator to setForce32BitAddressing

Change-Id: I836b60f6b74eecf678cc9d56851797d0db176107

runtime/os_interface/linux/drm_memory_manager.cpp

@@ -43,7 +43,6 @@ namespace OCLRT {
 
 DrmMemoryManager::DrmMemoryManager(Drm *drm, gemCloseWorkerMode mode, bool forcePinAllowed) : MemoryManager(false), drm(drm), pinBB(nullptr) {
     MemoryManager::virtualPaddingAvailable = true;
-    allocator32Bit = std::unique_ptr<Allocator32bit>(new Allocator32bit);
     if (mode != gemCloseWorkerMode::gemCloseWorkerInactive) {
         gemCloseWorker.reset(new DrmGemCloseWorker(*this));
     }