spl: if MMCSD_MODE_RAW fails, try MMCSD_MODE_FS, if available

In SPL MMC, boot modes are exclusive. So, if MMCSD_MODE_RAW fails, the board hangs. This patch allows to
try MMCSD_MODE_FS then, if available.

It has been tested on a pandaboard (rev. A3).

Signed-off-by: Guillaume GARDET <guillaume.gardet@free.fr>
Cc: Tom Rini <trini@ti.com>

common/spl/spl_mmc.c

@@ -123,7 +123,8 @@ void spl_mmc_load_image(void)
 			CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR);
 #endif
 #if defined(CONFIG_SPL_FAT_SUPPORT) || defined(CONFIG_SPL_EXT_SUPPORT)
-	} else if (boot_mode == MMCSD_MODE_FS) {
+	}
+	if (err || boot_mode == MMCSD_MODE_FS) {
 		debug("boot mode - FS\n");
 #ifdef CONFIG_SPL_FAT_SUPPORT
 #ifdef CONFIG_SPL_OS_BOOT