meta-phosphor: prep for new override syntax

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I588025b614416c43aa2d053765ab53bacf890cb5
diff --git a/meta-phosphor/conf/machine/include/obmc-bsp-common.inc b/meta-phosphor/conf/machine/include/obmc-bsp-common.inc
index 8a3da11..158c569 100644
--- a/meta-phosphor/conf/machine/include/obmc-bsp-common.inc
+++ b/meta-phosphor/conf/machine/include/obmc-bsp-common.inc
@@ -26,4 +26,4 @@
 INITRAMFS_CTYPE ?= "xz"
 INITRAMFS_FSTYPES = "cpio.${INITRAMFS_CTYPE}"
 INITRAMFS_IMAGE = "obmc-phosphor-initramfs"
-INITRAMFS_IMAGE_df-obmc-ubi-fs = ""
+INITRAMFS_IMAGE:df-obmc-ubi-fs = ""