Kernel: Store memory region size as uint64_t

On 32 bit target, we were storing 32 bit physical region sizes which
would truncate regions > 4 GiB

kernel/include/kernel/BootInfo.h

@@ -44,7 +44,7 @@ namespace Kernel
 	struct BootModule
 	{
 		paddr_t start;
-		size_t size;
+		uint64_t size;
 	};
 
 	struct BootInfo

kernel/include/kernel/Memory/PhysicalRange.h

@@ -10,7 +10,7 @@ namespace Kernel
 	class PhysicalRange
 	{
 	public:
-		PhysicalRange(paddr_t, size_t);
+		PhysicalRange(paddr_t, uint64_t);
 
 		paddr_t reserve_page();
 		void release_page(paddr_t);