Support for nonstandard baud rate in SetCommState.

diff --git a/configure.ac b/configure.ac
index 93615be..f2d6680 100644
--- a/configure.ac
+++ b/configure.ac
@@ -885,6 +885,7 @@
 	linux/cdrom.h \
 	linux/input.h \
 	linux/joystick.h \
+	linux/serial.h \
 	linux/ucdrom.h \
 	net/if.h \
 	netdb.h \