clk: qcom: Remove vdd class voting for xo clock

Remove vdd class from the rcg for video_xo_clk_src to avoid voltage voting
from the branch clock which is marked as always on.

Change-Id: I7a0e452d060c580761e9a8cac2cba4daf00d526b
Signed-off-by: Taniya Das <tdas@codeaurora.org>