Add Solaris native aio engine

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/options.c b/options.c
index 5aad005..cc131a2 100644
--- a/options.c
+++ b/options.c
@@ -557,6 +557,11 @@
 			    .help = "POSIX asynchronous IO",
 			  },
 #endif
+#ifdef FIO_HAVE_SOLARISAIO
+			  { .ival = "solarisaio",
+			    .help = "Solaris native asynchronous IO",
+			  },
+#endif
 			  { .ival = "mmap",
 			    .help = "Memory mapped IO",
 			  },