m68k: Multi-platform EARLY_PRINTK

Make the boot console available to more m68k platforms by leveraging
the head.S debug console.

The boot console is enabled by the "earlyprintk" command line argument
which is how most other architectures do this.

This is a change of behaviour for the Mac but does not negatively impact
the common use-case which is not debugging.

This is also a change of behaviour for other platforms because it means
the serial port stays quiet when CONFIG_EARLY_PRINTK is not enabled. This
is also an improvement for the common use-case.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stephen N Chivers <schivers@csc.com.au>
[Geert: CONSOLE_DEBUG should depend on CONFIG_FONT_SUPPORT]
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

arch/m68k/mac/config.c

@@ -71,31 +71,6 @@ static void mac_get_model(char *str);
 static void mac_identify(void);
 static void mac_report_hardware(void);
 
-#ifdef CONFIG_EARLY_PRINTK
-asmlinkage void __init mac_early_print(const char *s, unsigned n);
-
-static void __init mac_early_cons_write(struct console *con,
-                                 const char *s, unsigned n)
-{
-	mac_early_print(s, n);
-}
-
-static struct console __initdata mac_early_cons = {
-	.name  = "early",
-	.write = mac_early_cons_write,
-	.flags = CON_PRINTBUFFER | CON_BOOT,
-	.index = -1
-};
-
-int __init mac_unregister_early_cons(void)
-{
-	/* mac_early_print can't be used after init sections are discarded */
-	return unregister_console(&mac_early_cons);
-}
-
-late_initcall(mac_unregister_early_cons);
-#endif
-
 static void __init mac_sched_init(irq_handler_t vector)
 {
 	via_init_clock(vector);
@@ -190,10 +165,6 @@ void __init config_mac(void)
 	mach_beep = mac_mksound;
 #endif
 
-#ifdef CONFIG_EARLY_PRINTK
-	register_console(&mac_early_cons);
-#endif
-
 	/*
 	 * Determine hardware present
 	 */