* enable random on avr, it does not increase program size if not used

rtl/embedded/system.cfg

@@ -35,6 +35,10 @@
 # include exit code support
 -SfEXITCODE
 
+#ifdef CPUAVR
+-SfRANDOM
+#endif CPUAVR
+
 # i386 is powerful enough to handle most object pascal constructs
 # it is only a matter of size
 #ifdef CPUI386