env: Initialise all the environments

Since we want to have multiple environments, we will need to initialise
all the environments since we don't know at init time what drivers might
fail when calling load.

Let's init all of them, and only consider for further operations the ones
that have not reported any errors at init time.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

include/asm-generic/global_data.h

@@ -50,6 +50,7 @@ typedef struct global_data {
 #endif
 	unsigned long env_addr;		/* Address  of Environment struct */
 	unsigned long env_valid;	/* Environment valid? enum env_valid */
+	unsigned long env_has_init;	/* Bitmask of boolean of struct env_location offsets */
 
 	unsigned long ram_top;		/* Top address of RAM used by U-Boot */
 	unsigned long relocaddr;	/* Start address of U-Boot in RAM */