keystone: set default pci mode to root complex

pci ports are used as root complex in Linux. So set this as default
in u-boot for keystone devices

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
diff --git a/arch/arm/include/asm/arch-keystone/hardware.h b/arch/arm/include/asm/arch-keystone/hardware.h
index be22bdb..16cbcee 100644
--- a/arch/arm/include/asm/arch-keystone/hardware.h
+++ b/arch/arm/include/asm/arch-keystone/hardware.h
@@ -144,6 +144,7 @@
 #define KS2_DEVICE_STATE_CTRL_BASE	0x02620000
 #define KS2_JTAG_ID_REG			(KS2_DEVICE_STATE_CTRL_BASE + 0x18)
 #define KS2_DEVSTAT			(KS2_DEVICE_STATE_CTRL_BASE + 0x20)
+#define KS2_DEVCFG			(KS2_DEVICE_STATE_CTRL_BASE + 0x14c)
 
 /* PSC */
 #define KS2_PSC_BASE			0x02350000