spi: cadence_qspi: Enable apb linear mode for apb read & write operations

spi: cadence_qspi: Enable apb linear mode for apb read & write operations

On versal platform, enable apb linear mode for apb read and write
execute operations amd disable it when using dma reads. This is done by
xilinx_pm_request() secure calls when CONFIG_ZYNQMP_FIRMWARE is enabled,
else we use direct raw reads and writes in case of mini U-Boot.

Signed-off-by: T Karthik Reddy <[email protected]>
Signed-off-by: Ashok Reddy Soma <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Michal Simek <[email protected]>