dt-bindings: clock: Add RPMHCC bindings for SM8250

Add bindings and update documentation for clock rpmh driver on SM8250.

Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Taniya Das <tdas@codeaurora.org>
Signed-off-by: Venkata Narendra Kumar Gutta <vnkgutta@codeaurora.org>
Link: https://lkml.kernel.org/r/1579905147-12142-2-git-send-email-vnkgutta@codeaurora.org


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