Documentation: NFS/RDMA: Document separate Kconfig symbols

The NFS/RDMA Kconfig symbol was split into separate options for client
and server in commit 2e8c12e1b765 ("xprtrdma: add separate Kconfig
options for NFSoRDMA client and server support").

Update the documentation to reflect this split.

Signed-off-by: Paul Bolle <[e-mail]>
Reviewed-by: Jeff Layton <[e-mail]>
Signed-off-by: Randy Dunlap <[e-mail]>
Cc: "J. Bruce Fields" <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

Documentation/filesystems/nfs/nfs-rdma.txt

···
   - Build, install, reboot
 
     The NFS/RDMA code will be enabled automatically if NFS and RDMA
-    are turned on. The NFS/RDMA client and server are configured via the hidden
-    SUNRPC_XPRT_RDMA config option that depends on SUNRPC and INFINIBAND. The
-    value of SUNRPC_XPRT_RDMA will be:
+    are turned on. The NFS/RDMA client and server are configured via the
+    SUNRPC_XPRT_RDMA_CLIENT and SUNRPC_XPRT_RDMA_SERVER config options that both
+    depend on SUNRPC and INFINIBAND. The default value of both options will be:
 
      - N if either SUNRPC or INFINIBAND are N, in this case the NFS/RDMA client
        and server will not be built
···
 
   - Start the NFS server
 
-    If the NFS/RDMA server was built as a module (CONFIG_SUNRPC_XPRT_RDMA=m in
-    kernel config), load the RDMA transport module:
+    If the NFS/RDMA server was built as a module
+    (CONFIG_SUNRPC_XPRT_RDMA_SERVER=m in kernel config), load the RDMA
+    transport module:
 
     $ modprobe svcrdma
 
···
 
   - On the client system
 
-    If the NFS/RDMA client was built as a module (CONFIG_SUNRPC_XPRT_RDMA=m in
-    kernel config), load the RDMA client module:
+    If the NFS/RDMA client was built as a module
+    (CONFIG_SUNRPC_XPRT_RDMA_CLIENT=m in kernel config), load the RDMA client
+    module:
 
     $ modprobe xprtrdma.ko