dt-bindings: vendor-prefixes: Add Allwinner D1/D1s board vendors

dt-bindings: vendor-prefixes: Add Allwinner D1/D1s board vendors

Some boards using the Allwinner D1 or D1s SoC are made by vendors not
previously documented.

Clockwork Tech LLC (https://www.clockworkpi.com/) manufactures the
ClockworkPi and DevTerm boards.

Beijing Widora Technology Co., Ltd. (https://mangopi.cc/) manufactures
the MangoPi family of boards.

Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230126045738.47903-3-samuel@sholland.org
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>