Add LFSR generator

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fio.h b/fio.h
index 654db5f..0100e3d 100644
--- a/fio.h
+++ b/fio.h
@@ -181,6 +181,8 @@
 	double zipf_theta;
 	double pareto_h;
 
+	unsigned int random_generator;
+
 	unsigned int hugepage_size;
 	unsigned int rw_min_bs;
 	unsigned int thinktime;
@@ -822,4 +824,9 @@
 	FIO_RAND_DIST_PARETO,
 };
 
+enum {
+	FIO_RAND_GEN_TAUSWORTHE = 0,
+	FIO_RAND_GEN_LFSR,
+};
+
 #endif