Add support for Winbond's W25PXX SPI flash. These devices is used on Faraday A369 evaluation board. Signed-off-by: Kuo-Jung Su <dantesu@faraday-tech.com> CC: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com> CC: Tom Rini <trini@ti.com> Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>