Revert "clk: qcom: gcc-bengal: Update flag for gpll8_out_main clk"

This reverts commit 8b21a3e5.

To switch gcc_camss_ope_clk_src to all supported frequency,
gpll8_out_main need the CLK_SET_RATE_PARENT flag. So, revert the
change.

Change-Id: I4eb4845009c33d4310b67104886b66fbef8b7704
Signed-off-by: Naveen Yadav <naveenky@codeaurora.org>