LICENSES: add 0BSD license text

The license text was copied from:

https://spdx.org/licenses/0BSD.html

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Lasse Collin <[e-mail]>
Reviewed-by: Sam James <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: Greg Kroah-Hartman <[e-mail]>
Cc: Albert Ou <[e-mail]>
Cc: Catalin Marinas <[e-mail]>
Cc: Emil Renner Berthing <[e-mail]>
Cc: Herbert Xu <[e-mail]>
Cc: Joel Stanley <[e-mail]>
Cc: Jonathan Corbet <[e-mail]>
Cc: Jubin Zhong <[e-mail]>
Cc: Jules Maselbas <[e-mail]>
Cc: Krzysztof Kozlowski <[e-mail]>
Cc: Michael Ellerman <[e-mail]>
Cc: Palmer Dabbelt <[e-mail]>
Cc: Paul Walmsley <[e-mail]>
Cc: Randy Dunlap <[e-mail]>
Cc: Rui Li <[e-mail]>
Cc: Simon Glass <[e-mail]>
Cc: Will Deacon <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

LICENSES/deprecated/0BSD

···
+Valid-License-Identifier: 0BSD
+SPDX-URL: https://spdx.org/licenses/0BSD.html
+Usage-Guide:
+  To use the BSD Zero Clause License put the following SPDX tag/value
+  pair into a comment according to the placement guidelines in the
+  licensing rules documentation:
+    SPDX-License-Identifier: 0BSD
+License-Text:
+
+BSD Zero Clause License
+
+Copyright (c) <year> <copyright holders>
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.