Portability fixes for LSB compatibility.

diff --git a/configure.ac b/configure.ac
index a605aff..6f8aaed 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1078,6 +1078,7 @@
 	linux/cdrom.h \
 	linux/hdreg.h \
 	linux/input.h \
+	linux/ioctl.h \
 	linux/joystick.h \
 	linux/major.h \
 	linux/param.h \