s390/sclp: disable early sclp code as soon as the base sclp driver is active

Make sure the early sclp code does not generate any sclp requests
anymore as soon as the base sclp driver is active. Otherwise both
drivers may see unexpected requests or may miss expected interrupts.

Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/char/sclp.h

@@ -211,6 +211,13 @@ int sclp_sync_request_timeout(sclp_cmdw_t command, void *sccb, int timeout);
 int sclp_sdias_init(void);
 void sclp_sdias_exit(void);
 
+enum {
+	sclp_init_state_uninitialized,
+	sclp_init_state_initializing,
+	sclp_init_state_initialized
+};
+
+extern int sclp_init_state;
 extern int sclp_console_pages;
 extern int sclp_console_drop;
 extern unsigned long sclp_console_full;