The parameters ECC Strength, BadBlockMarkerByte and BadBlockMarkerStartBit in
the FCB structure depends on the nand chip's pagesize and oobsize. Instead of
hardcoding these values into the imx6 bbu handler calculate these values on the
fly. Therefore we export the necessary functions from the nand_mxs driver to
use them in the bbu handler.

Signed-off-by: Stefan Christ <s.christ@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>