spi: nxp-flexspi: Fix ARCH_LAYERSCAPE dependency

Currently the NXP Flex SPI driver has a dependency on ARCH_LAYERSCAPE ||
HAS_IOMEM which means that the dependency is almost always true and the
driver available. Really these should be two separate dependencies, with
an || COMPILE_TEST dependency for the architecture to ensure build coverage
is maintained.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230221-spi-arch-deps-v1-3-83d1566474cf@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/Kconfig

@@ -406,7 +406,8 @@ config SPI_HISI_SFC_V3XX
 
 config SPI_NXP_FLEXSPI
 	tristate "NXP Flex SPI controller"
-	depends on ARCH_LAYERSCAPE || HAS_IOMEM
+	depends on ARCH_LAYERSCAPE || COMPILE_TEST
+	depends on HAS_IOMEM
 	help
 	  This enables support for the Flex SPI controller in master mode.
 	  Up to four slave devices can be connected on two buses with two