clk: qcom: rcg2: set default freq to clk_gfx3d_src

This is a fix to set clk_gfx3d_src rate to the frequency from the
frequency table as a default frequency.

Change-Id: Idc980a99db10a2b60fcd8e926db2f38c864a5358
Signed-off-by: Asha Magadi Venkateshamurthy <amagad@codeaurora.org>