[S390] Fix appldata build break with !NET

With CONFIG_NET not set appldata build breaks on s390.

arch/s390/appldata/built-in.o: In function appldata_get_net_sum_data:
appldata_net_sum.c:(.text+0x2684): undefined reference to dev_get_stats
appldata_net_sum.c:(.text+0x2688): undefined reference to init_net
appldata_net_sum.c:(.text+0x268c): undefined reference to init_net
appldata_net_sum.c:(.text+0x2694): undefined reference to dev_base_lock

The following patch fixes the issue for me.
Signed-off-by: Sachin Sant <sachinp@in.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/Kconfig

@@ -521,7 +521,7 @@ config APPLDATA_OS
 
 config APPLDATA_NET_SUM
 	tristate "Monitor overall network statistics"
-	depends on APPLDATA_BASE
+	depends on APPLDATA_BASE && NET
 	help
 	  This provides network related data to the Linux - VM Monitor Stream,
 	  currently there is only a total sum of network I/O statistics, no