ARM: dts: remove STiH415-b2020.dts

Since v4.8, STiH415/416 clock support has
been removed [1], these platform doesn't boot.
We can remove DTS files related to these socs.

[1] https://patchwork.kernel.org/patch/9157571/Signed-off-by: Patrice Chotard <patrice.chotard@st.com>

arch/arm/boot/dts/Makefile

@@ -713,7 +713,6 @@ dtb-$(CONFIG_ARCH_STI) += \
 	stih410-b2120.dtb \
 	stih410-b2260.dtb \
 	stih415-b2000.dtb \
-	stih415-b2020.dtb \
 	stih418-b2199.dtb
 dtb-$(CONFIG_ARCH_STM32)+= \
 	stm32f429-disco.dtb \

arch/arm/boot/dts/stih415-b2020.dts

-/*
- * Copyright (C) 2013 STMicroelectronics (R&D) Limited.
- * Author: Srinivas Kandagatla <srinivas.kandagatla@st.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * publishhed by the Free Software Foundation.
- */
-/dts-v1/;
-#include "stih415.dtsi"
-#include "stih41x-b2020.dtsi"
-/ {
-	model = "STiH415 B2020 Board";
-	compatible = "st,stih415-b2020", "st,stih415";
-};