drm/tegra: dp: fix kernel-doc warnings in dp.h

drm/tegra: dp: fix kernel-doc warnings in dp.h

Use correct kernel-doc format and add missing nested struct entries to
eliminate kernel-doc warnings:

Warning: drivers/gpu/drm/tegra/dp.h:28 Incorrect use of kernel-doc format:
 * tps3_supported:
Warning: drivers/gpu/drm/tegra/dp.h:54 struct member 'tps3_supported'
 not described in 'drm_dp_link_caps'
dp.h:73: warning: Function parameter or struct member 'apply_training'
 not described in 'drm_dp_link_ops'
dp.h:73: warning: Function parameter or struct member 'configure'
 not described in 'drm_dp_link_ops'
dp.h:160: warning: Excess struct member 'cr' description in 'drm_dp_link'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patch.msgid.link/20260427184442.693768-1-rdunlap@infradead.org