Implement default versions of falcon mode functions to make the
CONFIG_SPL_OS_BOOT check in spl_mmc_load_image() unnecessary, thus reducing
its #ifdef complexity.

No functional changes.

Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
Cc: Igor Grinberg <grinberg@compulab.co.il>
Cc: Paul Kocialkowski <contact@paulk.fr>
Cc: Pantelis Antoniou <panto@antoniou-consulting.com>
Cc: Tom Rini <trini@konsulko.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Guillaume GARDET <guillaume.gardet@free.fr>
Cc: Suriyan Ramasami <suriyan.r@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>

Commit 9f12cd0e062614e19734b2ab37842d387457c5e5 has broken SPL EXT support.
This patch update error code check to get SPL EXT support working again.

Tested on a Pandaboard (rev. A3).

Reviewed-by: Suriyan Ramasami <suriyan.r@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Guillaume GARDET <guillaume.gardet@free.fr>
Cc: Tom Rini <trini@ti.com>

Change the internal EXT4 functions to use loff_t for offsets.

Signed-off-by: Suriyan Ramasami <suriyan.r@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
[trini: Update common/spl/spl_ext.c]
Signed-off-by: Tom Rini <trini@ti.com>

Add EXT filesystem support to SPL.

Signed-off-by: Guillaume GARDET <guillaume.gardet@free.fr>
[trini: Fix a warning and checkpatch problems]
Signed-off-by: Tom Rini <trini@ti.com>