spi-nor: spi-nor-ids: Disable SPI_NOR_4B_OPCODES for n25q512* and n25q256*

Per datasheets of n25q256* and n25q512* not all variants of n25q256* and
n25q512* support 4 Byte stateless addressing opcodes. Therefore drop
SPI_NOR_4B_OPCODES flag from these entries

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Tested-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Tested-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>