powerpc: make iSeries boot

Now that we use the device tree, it helps to build it in.
It helps to links the kernel at the correct address.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 7f891eb..34be324 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -317,7 +317,7 @@
 
 config PPC_OF
 	bool
-	depends on PPC_MULTIPLATFORM	# for now
+	depends on PPC_MULTIPLATFORM || PPC_ISERIES
 	default y
 
 config XICS
@@ -836,7 +836,7 @@
 if PPC64
 config KERNEL_START
 	hex
-	default "0xc0000000"
+	default "0xc000000000000000"
 endif
 
 source "net/Kconfig"