msm: vidc: fix clock voting for back to back video encoding

When V4L2 client calls stream_on-> stream_off ->stream_on sequence
for same session, incorrect instance state (i.e RELEASE_RESOURCES_DONE)
observed after submitting new set of buffers for second stream_on.
Due to no intermediate state exist between open_done and start_done,
call scale clocks after instance state moves to start_done
to ensure proper clocks are voted.

Change-Id: Iaa2d7083ab221794456ca4e8b02af24799a155e7
Signed-off-by: Srinu Gorle <sgorle@codeaurora.org>