mtd: nand: fsmc: reduce number of arguments of fsmc_nand_setup()

In preparation for the introduction of support for using SDR timings
exposed by the NAND flash instead of hard-coded timings, this commit
reworks the fsmc_nand_setup() function to take a "struct fsmc_nand_data"
as argument, which already contains the I/O registers base address, bank
and bus width information.

The timings is also currently contained in the "struct fsmc_nand_data",
but we still pass it as a separate argument because the support for
using SDR timings will pass a different value.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>