spl: Add EXT support to SPL

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>
diff --git a/fs/Makefile b/fs/Makefile
index 1822165..51d06fc 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -8,6 +8,7 @@
 
 ifdef CONFIG_SPL_BUILD
 obj-$(CONFIG_SPL_FAT_SUPPORT) += fat/
+obj-$(CONFIG_SPL_EXT_SUPPORT) += ext4/
 else
 obj-y				+= fs.o