Move arch/ppc to arch/powerpc

As discussed on the list, move "arch/ppc" to "arch/powerpc" to
better match the Linux directory structure.

Please note that this patch also changes the "ppc" target in
MAKEALL to "powerpc" to match this new infrastructure. But "ppc"
is kept as an alias for now, to not break compatibility with
scripts using this name.

Signed-off-by: Stefan Roese <sr@denx.de>
Acked-by: Wolfgang Denk <wd@denx.de>
Acked-by: Detlev Zundel <dzu@denx.de>
Acked-by: Kim Phillips <kim.phillips@freescale.com>
Cc: Peter Tyser <ptyser@xes-inc.com>
Cc: Anatolij Gustschin <agust@denx.de>
diff --git a/board/esd/cpci750/mv_eth.c b/board/esd/cpci750/mv_eth.c
index 1c21527..dedf734 100644
--- a/board/esd/cpci750/mv_eth.c
+++ b/board/esd/cpci750/mv_eth.c
@@ -1062,7 +1062,7 @@
 *************************************************************************/
 /*
  * based on Linux code
- * arch/ppc/galileo/EVB64360/mv64360_eth.c - Driver for MV64360X ethernet ports
+ * arch/powerpc/galileo/EVB64360/mv64360_eth.c - Driver for MV64360X ethernet ports
  * Copyright (C) 2002 rabeeh@galileo.co.il
 
  * This program is free software; you can redistribute it and/or