cadence_qspi: Refactor the flash reset functionality

cadence_qspi: Refactor the flash reset functionality

As the flash reset is handled in spi nor core, removing the
flash reset functionality. As the configuration like tristate
and hysterisis need to be enabled by the cdo. Handle the flash
reset only for mini u-boot case.

Rename the "cadence_qspi_versal_flash_reset" to generic name
"cadence_qspi_flash_reset" as this can be used by other platforms
as well.

Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@amd.com>
Link: https://lore.kernel.org/r/20241108063537.13180-1-venkatesh.abbarapu@amd.com
Signed-off-by: Michal Simek <michal.simek@amd.com>