lib/spd_bin,soc/intel/common: Move get_spd_smbus()

Only smbuslib.c and spd_bin.c share the same prototypes for SMBUS
functions. Therefore, get_spd_smbus() currently only works with
soc/intel/.../smbuslib.c and can be implemented there locally.

This allows removal of <device/early_smbus.h>.

Change-Id: Ic2d9d83ede6388a01d40c6e4768f6bb6bf899c00
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38121
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/include/device/early_smbus.h

@@ -1,56 +0,0 @@
-/*
- * This file is part of the coreboot project.
- *
- * Copyright (C) 2011  Alexandru Gagniuc <mr.nuke.me@gmail.com>
- *
- * 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.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
-
-/**
- * @file device/early_smbus.h
- *
- * This file defines a common API for accessing the SMBus during early
- * initialization. It defines the prototypes for common SMBus functions. The
- * actual implementations are hardware-dependent.
- *
- * The first parameter of all SMBus functions take a u32 value smbus_dev which
- * represents some information on how to access the device, and is
- * implementation defined. Usually, it just contains the IO base for the smbus.
- * To get this argument @ref smbus_get_device() can be used.
- *
- * The header only defines the prototypes. Several steps are needed to use
- * these:
- *
- * 1. Include this header
- * @code{.c}
- *	#include <device/early_smbus.h>
- * @endcode
- *
- * 2. Implement early_smbus.c for the hardware, or find a compatible
- * implementation.
- *
- * 3. Link against the file that implements these functions. In the Makefile.inc
- * of the chipset, add:
- * @code
- *	romstage-y += ./path/to/early_smbus.c
- * @endcode
- */
-
-#ifndef DEVICE_EARLY_SMBUS_H
-#define DEVICE_EARLY_SMBUS_H
-
-#include <stdint.h>
-
-u16 smbus_read_word(u8 addr, u8 offset);
-u8 smbus_read_byte(u8 addr, u8 offset);
-u8 smbus_write_byte(u8 addr, u8 offset, u8 value);
-
-#endif				/* DEVICE_EARLY_SMBUS_H */