1.Wait until all pending transfers from the generic controller are completed.
2.Disable the generic controller. Set GQSPI_En [GQSPI_EN] = 0.
3.Configure the legacy linear Quad-SPI controller.
4.Select the legacy linear Quad-SPI controller. Set LQSPI_CFG [LQ_MODE] = 1.
5.Enable the legacy linear controller. Set LQSPI_En [SPI_EN] = 1.
6.Use the legacy linear controller.