[yocto] librt within Yocto Recipe (beagle)

[Thomas Besemer]

I'm working with Beagleboard right now, stock top of tree from Yocto
pull.  GCC 4.7.2 builds fine.

I am able to use tools built during this process to link with librt
(-lrt) (as librt is in), but can't figure out how to do it from within
a Yocto/OE recipe.  I created a recipe to build my application, but it
complains that I don't have dependencies for librt (wants something).
My recipe:

DESCRIPTION = "GCPY Server application"
SECTION = "gcsim"
LICENSE = "MIT"
LIC_FILES_CHKSUM =
"file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"
PV = "1_0"

SRC_URI = "file://gcpy.tar"

S = "${WORKDIR}"

do_install() {
	install -d ${D}${base_libdir}
	install -m 0755 libgcpy_gc6016.so ${D}${base_libdir}
	install -d ${D}${bindir}
	install -m 0755 gcpy_gc6016_server ${D}${bindir}
}

There is a Makefile within tarball, and when I use the Yocto generated
tools outside of Yocto, builds fine.  Thus, I know librt is present
(and I see it).

What do I need in recipe to make this work?