clk: qcom: gcc-msm8998: Use parent_data/hws for internal clock relations

Use parent_data and parent_hws to specify internal relations using
pointers instead of names, and use .fw_name to retrieve external clocks
from clock-names in the DT rather than the global clock tree.

Note that this change relies on the "xo" and "sleep_clk" clocks to be
provided in DT, as per the relevant qcom,gcc-mnsm8998.yaml dt-bindings.
These clocks have been added in a prior patch [1].

[1]: https://lore.kernel.org/linux-arm-msm/20210911120101.248476-1-marijn.suijten@somainline.org/Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Link: https://lore.kernel.org/r/20210911121340.261920-3-marijn.suijten@somainline.orgSigned-off-by: Stephen Boyd <sboyd@kernel.org>