[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/memory_manager/memory_manager.cpp

@@ -213,6 +213,13 @@ std::unique_ptr<GraphicsAllocation> MemoryManager::obtainReusableAllocation(size
     return allocation;
 }
 
+void MemoryManager::setForce32BitAllocations(bool newValue) {
+    if (newValue && !this->allocator32Bit) {
+        this->allocator32Bit.reset(new Allocator32bit);
+    }
+    force32bitAllocations = newValue;
+}
+
 void MemoryManager::applyCommonCleanup() {
     if (this->paddingAllocation) {
         this->freeGraphicsMemory(this->paddingAllocation);