Kernel: Implement bare boness DMA Region

This does nothing but allocate contiguous physical and virtual memory
and map it as CacheDisable. Also memory is automatically freed RAII style.

kernel/CMakeLists.txt

@@ -34,6 +34,7 @@ set(KERNEL_SOURCES
 	kernel/Input/PS2Keymap.cpp
 	kernel/InterruptController.cpp
 	kernel/kernel.cpp
+	kernel/Memory/DMARegion.cpp
 	kernel/Memory/FileBackedRegion.cpp
 	kernel/Memory/GeneralAllocator.cpp
 	kernel/Memory/Heap.cpp