meta-ibm:system1:kernel: utilize correct device tree

The system1 device tree is now in openbmc/linux so utilize it

Change-Id: I1e4214483b17e4fe98375d5d3f56e98934d5eedd
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
diff --git a/meta-ibm/meta-system1/conf/machine/system1.conf b/meta-ibm/meta-system1/conf/machine/system1.conf
index c6b4b49..922e04c 100644
--- a/meta-ibm/meta-system1/conf/machine/system1.conf
+++ b/meta-ibm/meta-system1/conf/machine/system1.conf
@@ -1,6 +1,4 @@
-# TODO: Enable real device tree once available
-#KERNEL_DEVICETREE = "aspeed-bmc-ibm-system1.dtb"
-KERNEL_DEVICETREE = "aspeed/aspeed-ast2600-evb.dtb"
+KERNEL_DEVICETREE = "aspeed/aspeed-bmc-ibm-system1.dtb"
 
 UBOOT_MACHINE = "ast2600_openbmc_spl_emmc_defconfig"
 # Enable real device tree once available