mtd: nand: fsmc: kill {nr_, }partitions structure fields

The ->partitions and ->nr_partitions fields of struct
fsmc_nand_platform_data are never set anywhere, so they are always
NULL/0. The corresponding fields in 'struct fsmc_nand_data' are set to the
value of the same fields in fsmc_nand_platform_data, i.e NULL/0.

Therefore, we remove those two fields, and pass NULL/0 directly to
mtd_device_register(), like many other NAND drivers already do.

At the same time, we remove the comment about the fact that we pass
partition info, since we are no longer doing this.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>