meta-phosphor: add layer dependencies

These layers are all required, so add them to the layer dependencies.
This generates an error earlier in the build process when layers are
missing from the configuration (bblayers.conf).

The dependency list below is informative, but likely not comprehensive:

 -meta-python: python3-inflection-native
 -meta-networking: net-snmp
 -meta-oe: rsyslog, libvncserver, ipmitool, boost-url, libgpiod,
    lmsensors-config, openldap

Change-Id: I1b480224e6ec4b8bd61c8f21d6e569d17363a9a6
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-phosphor/conf/layer.conf b/meta-phosphor/conf/layer.conf
index addb6fc..a11ff8a 100644
--- a/meta-phosphor/conf/layer.conf
+++ b/meta-phosphor/conf/layer.conf
@@ -8,6 +8,10 @@
 BBFILE_COLLECTIONS += "phosphor-layer"
 BBFILE_PATTERN_phosphor-layer := "^${LAYERDIR}/"
 LAYERVERSION_phosphor-layer = "1"
+LAYERDEPENDS_phosphor-layer = "core"
+LAYERDEPENDS_phosphor-layer += "openembedded-layer"
+LAYERDEPENDS_phosphor-layer += "meta-python"
+LAYERDEPENDS_phosphor-layer += "networking-layer"
 LAYERSERIES_COMPAT_phosphor-layer = "honister kirkstone"
 
 IMAGE_FEATURES[validitems] += "tools-profile"