mtd: spi-nor: Introduce spi_nor_set_mtd_info()

mtd: spi-nor: Introduce spi_nor_set_mtd_info()

Used to init all the mtd_info fields. Move the mtd_info init
the last thing in the spi_nor_scan(), so that we avoid superfluous
initialization of the mtd_info fields in case of errors.

While here use common naming scheme for functions that are setting
mtd_info fields:
s/spi_nor_register_locking_ops/spi_nor_set_mtd_locking_ops
s/spi_nor_otp_init/spi_nor_set_mtd_otp_ops
The functions names are self explanatory, get rid of the comment
for the OTP function.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20211207140254.87681-4-tudor.ambarus@microchip.com