scsi: Move drivers into new drivers/scsi directory

At present we have the SCSI drivers in the drivers/block and common/
directories. It is better to split them out into their own place. Use
drivers/scsi which is what Linux does.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/block/Makefile b/drivers/block/Makefile
index 064c76f..a5e7307 100644
--- a/drivers/block/Makefile
+++ b/drivers/block/Makefile
@@ -13,6 +13,6 @@
 
 obj-$(CONFIG_IDE) += ide.o
 obj-$(CONFIG_IDE_FTIDE020) += ftide020.o
-obj-$(CONFIG_SANDBOX) += sandbox.o sandbox_scsi.o
+obj-$(CONFIG_SANDBOX) += sandbox.o
 obj-$(CONFIG_SYSTEMACE) += systemace.o
 obj-$(CONFIG_BLOCK_CACHE) += blkcache.o