add mkdev compatibility header for porting

Author: WinterMute

gc/sys/mkdev.h

@@ -0,0 +1,11 @@
+#ifndef __SYS_MKDEV_H__
+#define __SYS_MKDEV_H__
+
+#define MINORBITS       20
+#define MINORMASK       ((1U << MINORBITS) - 1)
+
+#define major(dev)      ((unsigned int) ((dev) >> MINORBITS))
+#define minor(dev)      ((unsigned int) ((dev) & MINORMASK))
+#define mkdev(ma,mi)    (((ma) << MINORBITS) | (mi))
+
+#endif