dt-bindings: clk: sprd: Add bindings for ums512 clock controller

Add a new bindings to describe ums512 clock compatible string.

Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Signed-off-by: Cixi Geng <cixi.geng1@unisoc.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220505101433.1575096-2-gengcixi@gmail.com


Signed-off-by: Stephen Boyd <sboyd@kernel.org>