clk: qcom: mmcc-8960: Add DSI related clocks

Add rcg and branch clk structs for DSI1 and DSI2 blocks found in MSM8960
and APQ8064. Each DSI instance has 4 pairs of rcg and branch clocks.
Populate arrays mmcc_msm8960_clks and mmcc_apq8064_clks with these clocks.

Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>