spi: spi-zynqmp-gqspi: fix incorrect operating mode in zynqmp_qspi_read_op

spi: spi-zynqmp-gqspi: fix incorrect operating mode in zynqmp_qspi_read_op

When starting a read operation, we should call zynqmp_qspi_setuprxdma
first to set xqspi->mode according to xqspi->bytes_to_receive and
to calculate correct xqspi->dma_rx_bytes. Then in the function
zynqmp_qspi_fillgenfifo, generate the appropriate command with
operating mode and bytes to transfer, and fill the GENFIFO with
the command to perform the read operation.

Calling zynqmp_qspi_fillgenfifo before zynqmp_qspi_setuprxdma will
result in incorrect transfer length and operating mode. So change
the calling order to fix this issue.

Fixes: 1c26372e5aa9 ("spi: spi-zynqmp-gqspi: Update driver to use spi-mem framework")
Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>
Reviewed-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@xilinx.com>
Link: https://lore.kernel.org/r/20210408040223.23134-5-quanyang.wang@windriver.com
Signed-off-by: Mark Brown <broonie@kernel.org>