udev: Fix build with eglibc 2.17

Link with librt to get definitions of mq_* functions
Fixes errors like below

 /home/kraj/work/angstrom/sources/openembedded-core/build/tmp-eglibc/work/armv5te-oe-linux-gnueabi/udev/182-r3/udev-182/src/sd-daemon.c:394:
undefined reference to `mq_getattr'
| collect2: error: ld returned 1 exit status

(From OE-Core rev: f8797bbba22e9b22bab3ddeb59cd3f33a816fa72)

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-core/udev/udev.inc

@@ -9,7 +9,8 @@ LICENSE_libgudev = "LGPLv2.1+"
 LIC_FILES_CHKSUM = "file://COPYING;md5=b234ee4d69f5fce4486a80fdaf4a4263 \
                     file://src/COPYING;md5=17c4e5fb495e6707ac92a3864926f979 \
                     file://src/gudev/COPYING;md5=fb494485a7d0505308cb68e4997cc266"
-                    
+
+LDFLAGS += "-lrt"
 
 DEPENDS = "acl glib-2.0 libusb usbutils pciutils gperf-native libxslt-native util-linux"
 RPROVIDES_${PN} = "hotplug"

meta/recipes-core/udev/udev_182.bb

@@ -1,6 +1,6 @@
 include udev.inc
 
-PR = "r3"
+PR = "r4"
 
 # module-init-tools from kmod_git will provide libkmod runtime
 DEPENDS += "module-init-tools"