[SPARC64]: Cleanup serial_console declarations.

arch/sparc64/kernel/power.c

@@ -11,6 +11,7 @@
 #include <linux/signal.h>
 #include <linux/delay.h>
 
+#include <asm/system.h>
 #include <asm/ebus.h>
 
 #define __KERNEL_SYSCALLS__
@@ -37,8 +38,6 @@ extern void machine_halt(void);
 extern void machine_alt_power_off(void);
 static void (*poweroff_method)(void) = machine_alt_power_off;
 
-extern int serial_console;
-
 void machine_power_off(void)
 {
 	if (!serial_console) {

arch/sparc64/kernel/process.c

@@ -110,7 +110,6 @@ int cpu_idle(void)
 extern char reboot_command [];
 
 extern void (*prom_palette)(int);
-extern int serial_console;
 extern void (*prom_keyboard)(void);
 
 void machine_halt(void)

arch/sparc64/kernel/setup.c

@@ -484,7 +484,6 @@ extern void paging_init(void);
 
 void __init setup_arch(char **cmdline_p)
 {
-	extern int serial_console;  /* in console.c, of course */
 	unsigned long highest_paddr;
 	int i;
 

arch/sparc64/prom/misc.c

@@ -14,6 +14,7 @@
 #include <linux/delay.h>
 #include <asm/openprom.h>
 #include <asm/oplib.h>
+#include <asm/system.h>
 
 /* Reset and reboot the machine with the command 'bcommand'. */
 void prom_reboot(char *bcommand)
@@ -33,7 +34,6 @@ void prom_feval(char *fstring)
 
 /* We want to do this more nicely some day. */
 extern void (*prom_palette)(int);
-extern int serial_console;
 
 #ifdef CONFIG_SMP
 extern void smp_capture(void);