clk: qcom: Add regmap mux-div clocks support

Add support for hardware that can switch both parent clocks and divider
at the same time. This avoids generating intermediate frequencies from
either the old parent clock and new divider or new parent clock and
old divider combinations.

Change-Id: I1b3f7e9422f5c27eeb391d309374167dc139e8ca
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Git-commit: 549f1a4028350851f73837ad8cce3ac5fd2abd11
Git-repo: https://git.quicinc.com/?p=kernel/msm-4.4.git


[anischal@codeaurora.org: Fix compilation issue with
mux_div_get_safe_parent]
Signed-off-by: Amit Nischal <anischal@codeaurora.org>