clk: qcom: dispcc-sm8250: Add additional parent clocks for DP

The clock controller has two additional clock source pairs, in order to
support more than a single DisplayPort PHY. List these, so it's possible
to describe them all.

Also drop the unnecessary freq_tbl for the link clock sources, to allow
these parents to be used.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20210721224610.3035258-1-bjorn.andersson@linaro.org


Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>