dm: sf: Make SST flash write op work again

With SPI flash moving to driver model, commit fbb0991 "dm: Convert
spi_flash_probe() and 'sf probe' to use driver model" ignored the
SST flash-specific write op (byte program & word program), which
actually broke the SST flash from wroking.

This commit makes SST flash work again under driver model, by adding
SST flash-specific handling in the spi_flash_std_write().

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>

drivers/mtd/spi/sf_probe.c

@@ -446,6 +446,15 @@ int spi_flash_std_write(struct udevice *dev, u32 offset, size_t len,
 {
 	struct spi_flash *flash = dev_get_uclass_priv(dev);
 
+#if defined(CONFIG_SPI_FLASH_SST)
+	if (flash->flags & SST_WR) {
+		if (flash->spi->op_mode_tx & SPI_OPM_TX_BP)
+			return sst_write_bp(flash, offset, len, buf);
+		else
+			return sst_write_wp(flash, offset, len, buf);
+	}
+#endif
+
 	return spi_flash_cmd_write_ops(flash, offset, len, buf);
 }