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/doc/README.LED b/doc/README.LED
index 94e552a..c3bcb3a 100644
--- a/doc/README.LED
+++ b/doc/README.LED
@@ -69,7 +69,7 @@
 blue_LED_on
 blue_LED_off
 
-These are weakly defined in lib_arm/board.c to noops. Where applicable, define
+These are weakly defined in arch/arm/lib/board.c to noops. Where applicable, define
 these functions in the board specific source.
 
 TBD : Describe older board dependent macros similar to what is done for