mtd: nand: sunxi: Add randomizer configuration before randomizer enable

In sunxi_nfc_hw_ecc_read_chunk(), the sunxi_nfc_randomizer_enable() is
called without the config of randomizer. A proper implementation can be
found in sunxi_nfc_hw_ecc_read_chunks_dma().

Add sunxi_nfc_randomizer_config() before the start of randomization.

Fixes: 4be4e03e ("mtd: nand: sunxi: add randomizer support")
Cc: stable@vger.kernel.org # v4.6
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>