rename environment.c in env_embedded.c to reflect is functionality

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/board/purple/u-boot.lds b/board/purple/u-boot.lds
index 972e6e7..09d6847 100644
--- a/board/purple/u-boot.lds
+++ b/board/purple/u-boot.lds
@@ -42,7 +42,7 @@
 	  common/cmd_boot.o		(.text)
 	  lib_generic/zlib.o		(.text)
 	  . = DEFINED(env_offset) ? env_offset : .;
-	  common/environment.o	(.ppcenv)
+	  common/env_embedded.o	(.ppcenv)
 
 	  *(.text)
 	}