ppc4xx: Invalidate d-cache when used as init-ram

We need to invalidate the data cache after it has been used as init-ram.

This problem was detected on the lwmon5 update.

Signed-off-by: Stefan Roese <sr@denx.de>

arch/powerpc/cpu/ppc4xx/start.S

@@ -1459,6 +1459,11 @@ relocate_code:
 	mtspr	SPRN_DTV3,r6
 	msync
 	isync
+
+	/* Invalidate data cache, now no longer our stack */
+	dccci	0,0
+	sync
+	isync
 #endif /* CONFIG_SYS_INIT_RAM_DCACHE */
 
 	/*