ANDROID: GKI: clk: Initialize in stack clk_init_data to 0 in all drivers

This allows adding fields to clk_init_data without having to explicitly
set those fields in all the drivers.

Bug: 150506629
Signed-off-by: Saravana Kannan <saravanak@google.com>
Change-Id: I0ff4e5108541b9f6e3e3e3f984a277b6954a629c