Revert "sandbox: move source files from board/ to arch/sandbox/"

This reverts commit 258060905e04fe2eb509756ef3b37e23e220a2d6.

Conflicts:
	boards.cfg

Wrong patch 25806090 was applied by accident. Revert it.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/sandbox/lib/Makefile b/arch/sandbox/lib/Makefile
index 6480ebf..4c1a38d 100644
--- a/arch/sandbox/lib/Makefile
+++ b/arch/sandbox/lib/Makefile
@@ -8,4 +8,4 @@
 #
 
 
-obj-y	+= interrupts.o sandbox.o
+obj-y	+= interrupts.o