mtd: nand: mtk: change the compile sequence of mtk_nand.o and mtk_ecc.o

There will get mtk ecc handler during mtk nand probe now.
If mtk ecc module is not initialized, then mtk nand probe will return
-EPROBE_DEFER, and retry later.

Change the compile sequence of mtk_nand.o and mtk_ecc.o, initialize mtk
ecc module before mtk nand module. This makes mtk nand module initialized
as soon as possible.

Signed-off-by: Xiaolei Li <xiaolei.li@mediatek.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>