meta-{aspeed,phosphor}: layer.conf: Override syntax cleanup

LAYERVERSION should keep underscore instead of colon.

Change-Id: I53b0af2fd8c756d09a11ee2c970910cdf7331738
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
diff --git a/meta-aspeed/conf/layer.conf b/meta-aspeed/conf/layer.conf
index 00302dd..21b9641 100644
--- a/meta-aspeed/conf/layer.conf
+++ b/meta-aspeed/conf/layer.conf
@@ -6,5 +6,5 @@
 
 BBFILE_COLLECTIONS += "aspeed-layer"
 BBFILE_PATTERN_aspeed-layer := "^${LAYERDIR}/"
-LAYERVERSION:aspeed-layer = "1"
+LAYERVERSION_aspeed-layer = "1"
 LAYERSERIES_COMPAT_aspeed-layer = "gatesgarth hardknott honister"