spi: cadence_qspi: Add support for Versal NET platform

Trivial changes to support cadence ospi driver for Versal NET platform.
Also avoid ospi flash reset for now.

Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/0789141f432189aab69bc496fe33e0218d1d7510.1663589964.git.michal.simek@amd.com