[POWERPC] PS3: Fix bootwrapper hang bug

Fix a bug in the lv1_get_repository_node_value() routine of the PS3
bootwrapper.  Changes in the PS3 system firmware 2.20 cause this bug
to hang the system when branching from the bootwrapper to the kernel
_start.

Since the video system has not yet been enabled at the time
the bug is hit, the system hangs with a blank screen.  Earlier
firmwares don't cause such a catastrophic failure, and so this
bug went undetected.
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/boot/ps3-hvcall.S

@@ -145,7 +145,7 @@
 .macro STORE_REGS_5_2
 	lwz r11, 16(r1)
 	std r4, 0(r11)
-	lwz r11, 24(r1)
+	lwz r11, 20(r1)
 	std r5, 0(r11)
 .endm