add new prom.h for AU1x00

Add new prom.h for AU1x00.

Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/arch/mips/au1000/pb1100/init.c b/arch/mips/au1000/pb1100/init.c
index 7ba6852..c93fd39 100644
--- a/arch/mips/au1000/pb1100/init.c
+++ b/arch/mips/au1000/pb1100/init.c
@@ -31,15 +31,13 @@
 #include <linux/mm.h>
 #include <linux/sched.h>
 #include <linux/bootmem.h>
-#include <asm/addrspace.h>
-#include <asm/bootinfo.h>
 #include <linux/string.h>
 #include <linux/kernel.h>
 
-int prom_argc;
-char **prom_argv, **prom_envp;
-extern void  __init prom_init_cmdline(void);
-extern char *prom_getenv(char *envname);
+#include <asm/addrspace.h>
+#include <asm/bootinfo.h>
+
+#include <prom.h>
 
 const char *get_system_type(void)
 {