clk: qcom: Add APQ8084 Multimedia Clock Controller (MMCC) support

Add support for the multimedia clock controller found on the APQ8084
based platforms. This will allow the multimedia device drivers to
control their clocks.

Signed-off-by: Georgi Djakov <gdjakov@mm-sol.com>
[sboyd: Rework parent mapping to avoid conflicts]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>