drm/tegra: hdmi: Make read-only const array freqs static

Don't populate the const read-only array freqs on the stack at run time,
instead make it static.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240822205047.642845-1-colin.i.king@gmail.com