powerpc: Merge in 64-bit powermac support.

This brings in a lot of changes from arch/ppc64/kernel/pmac_*.c to
arch/powerpc/platforms/powermac/*.c and makes various minor tweaks
elsewhere.  On the powermac we now initialize ppc_md by copying
the whole pmac_md structure into it, which required some changes in
the ordering of initializations of individual fields of it.

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index b9269c0..2d7fdeb 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -464,14 +464,11 @@
 	strlcpy(cmd_line, CONFIG_CMDLINE, sizeof(cmd_line));
 #endif /* CONFIG_CMDLINE */
 
+	platform_init();
+
 #ifdef CONFIG_6xx
 	ppc_md.power_save = ppc6xx_idle;
 #endif
-#ifdef CONFIG_POWER4
-	ppc_md.power_save = power4_idle;
-#endif
-
-	platform_init();
 
 	if (ppc_md.progress)
 		ppc_md.progress("id mach(): done", 0x200);