net/smc: Fix dependency of SMC on ISM

When the SMC protocol is built into the kernel proper while ISM is
configured to be built as module, linking the kernel fails due to
unresolved dependencies out of net/smc/smc_ism.o to
ism_get_smcd_ops, ism_register_client, and ism_unregister_client
as reported via the linux-next test automation (see link).
This however is a bug introduced a while ago.

Correct the dependency list in ISM's and SMC's Kconfig to reflect the
dependencies that are actually inverted. With this you cannot build a
kernel with CONFIG_SMC=y and CONFIG_ISM=m. Either ISM needs to be 'y',
too - or a 'n'. That way, SMC can still be configured on non-s390
architectures that do not have (nor need) an ISM driver.

Fixes: 89e7d2ba61 ("net/ism: Add new API for client registration")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Closes: https://lore.kernel.org/linux-next/d53b5b50-d894-4df8-8969-fd39e63440ae@infradead.org/
Co-developed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Simon Horman <horms@kernel.org> # build-tested
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Link: https://lore.kernel.org/r/20231006125847.1517840-1-gbayer@linux.ibm.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/s390/net/Kconfig

@@ -102,7 +102,7 @@ config CCWGROUP
 
 config ISM
 	tristate "Support for ISM vPCI Adapter"
-	depends on PCI && SMC
+	depends on PCI
 	default n
 	help
 	  Select this option if you want to use the Internal Shared Memory

net/smc/Kconfig

@@ -2,6 +2,7 @@
 config SMC
 	tristate "SMC socket protocol family"
 	depends on INET && INFINIBAND
+	depends on m || ISM != m
 	help
 	  SMC-R provides a "sockets over RDMA" solution making use of
 	  RDMA over Converged Ethernet (RoCE) technology to upgrade