sh-sci: Extend sh-sci driver with early console V2

This is V2 of early serial console support for the sh-sci
driver. The early serial console is using early platform
devices and "earlyprintk". To use this feature the early
platform devices must be broken out to one device per port
and the desired port should be selected on the kernel command
line like: "earlyprintk=sh-sci.N[,baudrate][,keep]"

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/early_printk.c

@@ -191,15 +191,7 @@ static void scif_sercon_init(char *s)
  * Setup a default console, if more than one is compiled in, rely on the
  * earlyprintk= parsing to give priority.
  */
-static struct console *early_console =
-#ifdef CONFIG_SH_STANDARD_BIOS
-	&bios_console
-#elif defined(CONFIG_EARLY_SCIF_CONSOLE)
-	&scif_console
-#else
-	NULL
-#endif
-	;
+static struct console *early_console;
 
 static int __init setup_early_printk(char *buf)
 {

arch/sh/kernel/setup.c

@@ -423,6 +423,9 @@ void __init setup_arch(char **cmdline_p)
 
 	plat_early_device_setup();
 
+	/* Let earlyprintk output early console messages */
+	early_platform_driver_probe("earlyprintk", 1, 1);
+
 	sh_mv_setup();
 
 	/*