fs/erofs: add erofs filesystem support

This patch mainly deals with uncompressed files.

Signed-off-by: Huang Jianan <jnhuang95@gmail.com>
diff --git a/fs/Makefile b/fs/Makefile
index 937cbcf..f05a21c 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -25,5 +25,6 @@
 obj-$(CONFIG_YAFFS2) += yaffs2/
 obj-$(CONFIG_CMD_ZFS) += zfs/
 obj-$(CONFIG_FS_SQUASHFS) += squashfs/
+obj-$(CONFIG_FS_EROFS) += erofs/
 endif
 obj-y += fs_internal.o