drivers/i2c/hid: Add generic I2C HID driver

Add a generic I2C-HID driver for these types of devices that
do not need extra functionality.  This allows a new device to
be added without having to write a new driver.

The i2c-hid PNP0C50 is automatically added as the _CID for the
device in the ACPI Device.

BUG=chrome-os-partner:58666
TEST=used on eve to describe a new i2c-hid touch controller

Change-Id: I94e9531a72f9bf1d6b3ade362b88883b21b83d0a
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://review.coreboot.org/17856
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)

src/drivers/i2c/hid/chip.h

@@ -0,0 +1,28 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2016 Google Inc.
+ *
+ * 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; version 2 of the License.
+ *
+ * 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.
+ */
+
+#ifndef __DRIVERS_I2C_HID_CHIP_H__
+#define __DRIVERS_I2C_HID_CHIP_H__
+
+#include <drivers/i2c/generic/chip.h>
+
+#define I2C_HID_CID	"PNP0C50"
+
+struct drivers_i2c_hid_config {
+	struct drivers_i2c_generic_config generic;
+	uint8_t hid_desc_reg_offset;
+};
+
+#endif /* __I2C_HID_CHIP_H__ */