p9dsu_defconfig: Remove BR2_OPENPOWER_PNOR_UPDATE_FILENAME

The p9dsu pnor is currently a single 64MB image, so there is no
need to have an update pnor file.

Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
diff --git a/openpower/configs/p9dsu_defconfig b/openpower/configs/p9dsu_defconfig
index 532e7b0..d82d443 100644
--- a/openpower/configs/p9dsu_defconfig
+++ b/openpower/configs/p9dsu_defconfig
@@ -50,7 +50,6 @@
 BR2_OPENPOWER_PNOR_XML_LAYOUT_FILENAME="defaultPnorLayout_64.xml"
 BR2_OPENPOWER_CONFIG_NAME="p9dsu"
 BR2_OPENPOWER_PNOR_FILENAME="p9dsu.pnor"
-BR2_OPENPOWER_PNOR_UPDATE_FILENAME="p9dsu_update.pnor"
 BR2_HOSTBOOT_BINARY_SBE_FILENAME="nimbus_sbe.img.ecc"
 BR2_HOSTBOOT_BINARY_SBEC_FILENAME="centaur_sbec_pad.img.ecc"
 BR2_HOSTBOOT_BINARY_WINK_FILENAME="p9n.ref_image.hdr.bin.ecc"