spi: spi-zynq-qspi: add spi-mem to driver kconfig dependencies

Zynq QSPI driver has been converted to use spi-mem framework so
add spi-mem to driver kconfig dependencies.

Fixes: 67dca5e5 ("spi: spi-mem: Add support for Zynq QSPI controller")
Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Link: https://lore.kernel.org/r/1699037031-702858-1-git-send-email-radhey.shyam.pandey@amd.com


Signed-off-by: Mark Brown <broonie@kernel.org>