powerpc: Change the default link address for pSeries zImage kernels

Currently we set the start of the .text section to be 4Mb for pSeries.
In situations where the zImage is > 8Mb we'll fail to boot (due to
overlapping with OF).  Move .text in a zImage from 4MB to 64MB
(well past OF).

We still will not be able to load large zImage unless we also move OF,
to that end, add a note to the zImage ELF to move OF to 32Mb.  If this
is the very first kernel booted then we'll need to move OF manually by
setting real-base.

Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/boot/addnote.c b/arch/powerpc/boot/addnote.c
index 8041a98..b1e5611 100644
--- a/arch/powerpc/boot/addnote.c
+++ b/arch/powerpc/boot/addnote.c
@@ -25,7 +25,7 @@
 #define N_DESCR	6
 unsigned int descr[N_DESCR] = {
 	0xffffffff,		/* real-mode = true */
-	0x00c00000,		/* real-base, i.e. where we expect OF to be */
+	0x02000000,		/* real-base, i.e. where we expect OF to be */
 	0xffffffff,		/* real-size */
 	0xffffffff,		/* virt-base */
 	0xffffffff,		/* virt-size */