[MIPS] Fix and cleanup the mess that a dozen prom_printf variants are.

early_printk is a so much saner thing.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/lasat/prom.h

@@ -2,5 +2,4 @@
 #define PROM_H
 extern void (* prom_display)(const char *string, int pos, int clear);
 extern void (* prom_monitor)(void);
-extern void (* prom_printf)(const char * fmt, ...);
 #endif