Add header that musl libc needs.
diff --git a/toys.h b/toys.h
index 40946d7..d7cf210 100644
--- a/toys.h
+++ b/toys.h
@@ -37,6 +37,7 @@
 #include <sys/statvfs.h>
 #include <sys/sysinfo.h>
 #include <sys/swap.h>
+#include <sys/time.h>
 #include <sys/times.h>
 #include <sys/types.h>
 #include <sys/utsname.h>