poky.conf: Bump version for 1.7.3 dizzy release

(From meta-yocto rev: 661f1023c499c490255ca5e97b76d54e51a8f59e)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta-yocto/conf/distro/poky.conf

@@ -1,6 +1,6 @@
 DISTRO = "poky"
 DISTRO_NAME = "Poky (Yocto Project Reference Distro)"
-DISTRO_VERSION = "1.7.2"
+DISTRO_VERSION = "1.7.3"
 DISTRO_CODENAME = "dizzy"
 SDK_VENDOR = "-pokysdk"
 SDK_VERSION := "${@'${DISTRO_VERSION}'.replace('snapshot-${DATE}','snapshot')}"