platform: msm: Add driver for QPNP PMIC clkdiv peripherals

This driver supports the Qualcomm PNP clkdiv peripheral. It
allowed for configuring divide factors for various clock outputs
on the PMIC. The source clock is CXO.

The driver allows for configuration of the clkdiv device through
Device Tree. Some optional parameters may be specified instead at
runtime with the qpnp_clkdiv_config() API.

Change-Id: I393ed0e4389fb3c1dfe0bcdb40944102d2e09894
Signed-off-by: Michael Bohan <mbohan@codeaurora.org>