clk: tegra: fix host1x clock on Tegra124

The host1x clock on Tegra124 is a 3-bit wide mux with 6 parents.
Change thte id to tegra_clk_host1x_8 so that the correct clock gets
registered.

Signed-off-by: Mark Zhang <markz@nvidia.com>
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>