Move environment files from common/ to env/

About a quarter of the files in common/ relate to the environment. It
seems better to put these into their own subdirectory and remove the
prefix.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>

arch/sh/cpu/u-boot.lds

@@ -33,9 +33,9 @@ SECTIONS
 		KEEP(CONFIG_BOARDDIR/lowlevel_init.o	(.text .spiboot1.text))
 		KEEP(*(.spiboot2.text))
 		. = ALIGN(8192);
-		common/env_embedded.o	(.ppcenv)
+		env/embedded.o	(.ppcenv)
 		. = ALIGN(8192);
-		common/env_embedded.o	(.ppcenvr)
+		env/embedded.o	(.ppcenvr)
 		. = ALIGN(8192);
 		*(.text)
 		. = ALIGN(4);