Move lib_$ARCH directories to arch/$ARCH/lib

Also move lib_$ARCH/config.mk to arch/$ARCH/config.mk

This change is intended to clean up the top-level directory structure
and more closely mimic Linux's directory organization.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/board/freescale/m54451evb/u-boot.stm b/board/freescale/m54451evb/u-boot.stm
index e9eac67..1b06b12 100644
--- a/board/freescale/m54451evb/u-boot.stm
+++ b/board/freescale/m54451evb/u-boot.stm
@@ -61,7 +61,7 @@
     cpu/mcf5445x/dspi.o			(.text)
     cpu/mcf5445x/interrupt.o		(.text)
     cpu/mcf5445x/speed.o		(.text)
-    lib_m68k/board.o			(.text)
+    arch/m68k/lib/board.o			(.text)
     common/serial.o			(.text)
     common/console.o			(.text)
     lib_generic/display_options.o	(.text)