MIPS: BCM47xx: Move NVRAM header to the include/linux/.

There are two reasons for having this header in the common place:
1) Simplifying drivers that read NVRAM entries. We will be able to
   safely call bcm47xx_nvram_* functions without #ifdef-s.
2) Getting NVRAM driver out of MIPS arch code. This is needed to support
   BCM5301X arch which also requires this NVRAM driver. Patch for that
   will follow once we get is reviewed.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Acked-by: Hauke Mehrtens <hauke@hauke-m.de>
Cc: linux-mips@linux-mips.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: linux-soc@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8619/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/mach-bcm47xx/bcm47xx.h

@@ -22,6 +22,7 @@
 #include <linux/ssb/ssb.h>
 #include <linux/bcma/bcma.h>
 #include <linux/bcma/bcma_soc.h>
+#include <linux/bcm47xx_nvram.h>
 
 enum bcm47xx_bus_type {
 #ifdef CONFIG_BCM47XX_SSB

arch/mips/include/asm/mach-bcm47xx/bcm47xx_nvram.h

@@ -1,21 +0,0 @@
-/*
- *  Copyright (C) 2005, Broadcom Corporation
- *  Copyright (C) 2006, Felix Fietkau <nbd@openwrt.org>
- *
- *  This program is free software; you can redistribute  it and/or modify it
- *  under  the terms of  the GNU General  Public License as published by the
- *  Free Software Foundation;  either version 2 of the  License, or (at your
- *  option) any later version.
- */
-
-#ifndef __BCM47XX_NVRAM_H
-#define __BCM47XX_NVRAM_H
-
-#include <linux/types.h>
-#include <linux/kernel.h>
-
-int bcm47xx_nvram_init_from_mem(u32 base, u32 lim);
-int bcm47xx_nvram_getenv(const char *name, char *val, size_t val_len);
-int bcm47xx_nvram_gpio_pin(const char *name);
-
-#endif /* __BCM47XX_NVRAM_H */