Include xorg-server.h to fix build errors on newest glibc

In file included from /usr/include/string.h:634:0,
                 from /usr/include/xorg/os.h:53,
                 from /usr/include/xorg/misc.h:115,
                 from /usr/include/xorg/xf86str.h:37,
                 from /usr/include/xorg/xf86Xinput.h:54,
                 from synproto.h:36,
                 from synproto.c:24:
/usr/include/xorg/os.h:579:1: error: expected identifier or '(' before '__extension__'
 strndup(const char *str, size_t n);

See http://lists.freedesktop.org/archives/xorg-devel/2014-July/043070.html

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

src/eventcomm.h

@@ -27,6 +27,8 @@
 #ifndef _EVENTCOMM_H_
 #define _EVENTCOMM_H_
 
+#include <xorg-server.h>
+
 #include <linux/input.h>
 #include <linux/version.h>
 #include <xf86Xinput.h>

src/ps2comm.h

@@ -22,6 +22,8 @@
 #ifndef _PS2COMM_H_
 #define _PS2COMM_H_
 
+#include <xorg-server.h>
+
 #include <unistd.h>
 #include <sys/ioctl.h>
 #include "xf86_OSproc.h"

src/synproto.h

@@ -31,6 +31,8 @@
 #include "config.h"
 #endif
 
+#include <xorg-server.h>
+
 #include <unistd.h>
 #include <sys/ioctl.h>
 #include <xf86Xinput.h>