power: Drop unused fg_max17042 driver and fuel gauge code

This driver is not used. Drop it and the entire fuel_gauge directory,
since there is nothing left.

Signed-off-by: Simon Glass <sjg@chromium.org>

include/power/fg_battery_cell_params.h

@@ -1,73 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0+ */
-/*
- *  Copyright (C) 2012 Samsung Electronics
- *  Lukasz Majewski <l.majewski@samsung.com>
- */
-
-#ifndef __FG_BATTERY_CELL_PARAMS_H_
-#define __FG_BATTERY_CELL_PARAMS_H_
-
-#if  defined(CONFIG_POWER_FG_MAX17042) && defined(CONFIG_TARGET_TRATS)
-
-/* Cell characteristics - Exynos4 TRATS development board */
-/* Shall be written to addr 0x80h */
-u16 cell_character0[16] = {
-	0xA2A0,
-	0xB6E0,
-	0xB850,
-	0xBAD0,
-	0xBB20,
-	0xBB70,
-	0xBBC0,
-	0xBC20,
-	0xBC80,
-	0xBCE0,
-	0xBD80,
-	0xBE20,
-	0xC090,
-	0xC420,
-	0xC910,
-	0xD070
-};
-
-/* Shall be written to addr 0x90h */
-u16 cell_character1[16] = {
-	0x0090,
-	0x1A50,
-	0x02F0,
-	0x2060,
-	0x2060,
-	0x2E60,
-	0x26A0,
-	0x2DB0,
-	0x2DB0,
-	0x1870,
-	0x2A20,
-	0x16F0,
-	0x08F0,
-	0x0D40,
-	0x08C0,
-	0x08C0
-};
-
-/* Shall be written to addr 0xA0h */
-u16 cell_character2[16] = {
-	0x0100,
-	0x0100,
-	0x0100,
-	0x0100,
-	0x0100,
-	0x0100,
-	0x0100,
-	0x0100,
-	0x0100,
-	0x0100,
-	0x0100,
-	0x0100,
-	0x0100,
-	0x0100,
-	0x0100,
-	0x0100
-};
-#endif
-#endif /* __FG_BATTERY_CELL_PARAMS_H_ */