driver: mtd: spi: Adding support for QSPI flash

Serial number, vendor id and page size are added for QSPI flash
common on both LS1012AQDS and LS1012ARDB i.e. S25FS512SDSMFI011.

Signed-off-by: Pratiyush Mohan Srivastava <pratiyush.srivastava@nxp.com>
Signed-off-by: Calvin Johnson <calvin.johnson@nxp.com>
Signed-off-by: Mingkai Hu <mingkai.hu@nxp.com>
Signed-off-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>