clk: qcom: Add enable/disable to clk_regmap_mux_div_ops

Add support for and enable and disable ops for regmap_mux_div clk, also
support for safe source for regmap_mux_div clock to park the clk to safe
source while disabling and restore to active rate when clk is enabled.

Change-Id: Ida765ec1853c2bdd17b6fce3e8012e294f4324fe
Signed-off-by: Taniya Das <tdas@codeaurora.org>