[cheese] Restore gudev checks during configure

[David King <davidk src gnome org>]

commit 6acece6bcc3a239cb374a9ed6fea813dbcdc63dd
Author: David King <amigadave amigadave com>
Date:   Tue Oct 25 17:33:17 2011 +0200

    Restore gudev checks during configure

 configure.ac |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 04d44d0..b23a9d4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -106,6 +106,14 @@ AS_CASE([$host_os],
     UDEV_REQUIRED="gudev-1.0"],
   [AC_MSG_RESULT([unsupported operating system])])
 
+AC_MSG_CHECKING([for gudev-1.0])
+AS_IF([test -n $UDEV_REQUIRED],
+  [PKG_CHECK_EXISTS([$UDEV_REQUIRED],
+    [AC_MSG_RESULT([found])
+     AC_DEFINE([HAVE_UDEV], [], [Enable gudev support])],
+    [AC_MSG_ERROR([$UDEV_REQUIRED not found])])],
+  [AC_MSG_RESULT([not needed])])
+
 AC_CHECK_HEADERS([sys/videoio.h])
 
 AC_CHECK_HEADER([X11/extensions/XTest.h],