Everywhere: Add serenity_dev_{makedev,major,minor}

Add them in `<Kernel/API/Device.h>` and use these to provides
`{makedev,major,minor}` in `<sys/sysmacros.h>`. It aims to be more in
line with other Unix implementations and avoid code duplication in user
land.

Userland/Utilities/ls.cpp

@@ -30,6 +30,7 @@
 #include <string.h>
 #include <sys/ioctl.h>
 #include <sys/stat.h>
+#include <sys/sysmacros.h>
 #include <sys/types.h>
 #include <time.h>
 #include <unistd.h>