riscv: Update SPDX license identifiers

The whole gnu-efi project is licensed under BSD license, see [1].
However some of the RISC-V codes have conflict license identifiers:

- Some mention GPL-2.0+ in the SPDX license part, but the long license
  header indicates it's actually BSD and GPL-2.0+ dual-licensed
- Some mention GPL-2.0+ in the SPDX license part only
- Some do not have any license indication

To have a matching license with the whole project, this commit updates
all RISC-V codes to have the correct SPDX license identifiers
(GPL-2.0+ or BSD dual-license).

Link: https://sourceforge.net/p/gnu-efi/ [1]
Signed-off-by: Bin Meng <bmeng@tinylab.org>
Acked-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

gnuefi/crt0-efi-riscv64.S

@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0+ */
+/* SPDX-License-Identifier: GPL-2.0+ OR BSD-2-Clause */
 /*
  * Copright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
  * Copright (C) 2018 Alexander Graf <agraf@suse.de>

gnuefi/elf_riscv64_efi.lds

@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0+ */
+/* SPDX-License-Identifier: GPL-2.0+ OR BSD-2-Clause */
 
 OUTPUT_FORMAT("elf64-littleriscv", "elf64-littleriscv", "elf64-littleriscv")
 OUTPUT_ARCH(riscv)

gnuefi/reloc_riscv64.c

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
 /* reloc_riscv.c - position independent ELF shared object relocator
    Copyright (C) 2018 Alexander Graf <agraf@suse.de>
    Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>

inc/riscv64/efibind.h

@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0+ OR BSD-2-Clause */
 /*
  * Copright (C) 2014 - 2015 Linaro Ltd.
  * Author: Ard Biesheuvel <ard.biesheuvel@linaro.org>

inc/riscv64/efilibplat.h

@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0+ */
+/* SPDX-License-Identifier: GPL-2.0+ OR BSD-2-Clause */
 
 VOID
 InitializeLibPlatform (

inc/riscv64/efisetjmp_arch.h

@@ -1,3 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0+ OR BSD-2-Clause */
+
 #ifndef GNU_EFI_RISCV64_SETJMP_H
 #define GNU_EFI_RISCV64_SETJMP_H
 

lib/riscv64/initplat.c

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+// SPDX-License-Identifier: GPL-2.0+ OR BSD-2-Clause
 
 #include "lib.h"
 

lib/riscv64/setjmp.S

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+// SPDX-License-Identifier: GPL-2.0+ OR BSD-2-Clause
 /*
  * Copyright Heinrich Schuchardt <xypron.glpk@gmx.de>
  */