dt-bindings: Add qcom spmi_pmic clock divider bindings

This patch adds device tree bindings for Qualcomm SPMI PMIC
clock divider module.

Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>
[sboyd: Moved file to match compatible of binding]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>