global_data: Use less space for environment fields

Use shorter types for some of these fields to save space. Reorder to put
fields with like alignment together.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h
index 86e8d654..1252b8a 100644
--- a/include/asm-generic/global_data.h
+++ b/include/asm-generic/global_data.h
@@ -114,21 +114,21 @@
 	 */
 	unsigned long env_addr;
 	/**
-	 * @env_valid: environment is valid
+	 * @env_has_init: bit mask indicating environment locations
 	 *
-	 * See &enum env_valid
+	 * &enum env_location defines which bit relates to which location
 	 */
-	unsigned long env_valid;
+	unsigned short env_has_init;
 	/**
-	 * @env_has_init: bit mask indicating environment locations
+	 * @env_valid: environment is valid
 	 *
-	 * &enum env_location defines which bit relates to which location
+	 * See &enum env_valid
 	 */
-	unsigned long env_has_init;
+	unsigned char env_valid;
 	/**
 	 * @env_load_prio: priority of the loaded environment
 	 */
-	int env_load_prio;
+	char env_load_prio;
 	/**
 	 * @ram_base: base address of RAM used by U-Boot
 	 */