dt-bindings: clock: fixed-factor: Drop Allwinner A10 compatible

dt-bindings: clock: fixed-factor: Drop Allwinner A10 compatible

This compatible is part of the legacy sunxi clock support, and has not
been used since commit 6b48644b1d29 ("ARM: gr8: Convert to CCU") in
October 2016. Now that the code for this compatible has been removed,
let's drop the compatible.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Link: https://lore.kernel.org/r/20220531051742.43273-2-samuel@sholland.org
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>