drm/amd/display: increase HDCP authentication delay

[Why]
Some displays have an issue where the hdcp chips are initialized after the
display has already lit up. This means we can sometimes authentication too early
and cause authentication failures.

This happens when HDCP is enabled and the display is power cycled. Normally we
will authenticate 2 seconds after the display is lit, but some displays need a
bit more time.

[How]
Increase delay to 3 second before we start authentication.

Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>