spi: spi-zynqmp-gqspi: fix hang issue when suspend/resume

After calling platform_set_drvdata(pdev, xqspi) in probe, the return
value of dev_get_drvdata(dev) is a pointer to struct zynqmp_qspi but
not struct spi_controller. A wrong structure type passing to the
functions spi_controller_suspend/resume will hang the system.

And we should check the return value of spi_controller_suspend, if
an error is returned, return it to PM subsystem to stop suspend.

Also, GQSPI_EN_MASK should be written to GQSPI_EN_OFST to enable
the spi controller in zynqmp_qspi_resume since it was disabled in
zynqmp_qspi_suspend before.

Fixes: 1c26372e

 ("spi: spi-zynqmp-gqspi: Update driver to use spi-mem framework")
Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>
Link: https://lore.kernel.org/r/20210416004652.2975446-3-quanyang.wang@windriver.com
Signed-off-by: Mark Brown <broonie@kernel.org>