powerpc: Enable device tree support for MPC8548CDS

Add device tree for MPC8548CDS board and enable CONFIG_OF_CONTROL
so that device tree can be compiled.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Reviewed-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>
diff --git a/configs/MPC8548CDS_defconfig b/configs/MPC8548CDS_defconfig
index 09726d2..72239da 100644
--- a/configs/MPC8548CDS_defconfig
+++ b/configs/MPC8548CDS_defconfig
@@ -1,8 +1,11 @@
 CONFIG_PPC=y
 CONFIG_SYS_TEXT_BASE=0xFFF80000
 CONFIG_MPC85xx=y
+CONFIG_MPC85XX_HAVE_RESET_VECTOR=y
 # CONFIG_CMD_ERRATA is not set
 CONFIG_TARGET_MPC8548CDS=y
+CONFIG_DEFAULT_DEVICE_TREE="mpc8548cds"
+CONFIG_OF_CONTROL=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_OF_STDOUT_VIA_ALIAS=y
 CONFIG_BOOTDELAY=10