drm/i915/dp: Reset link params after a DPRX capability change

drm/i915/dp: Reset link params after a DPRX capability change

There is no reason to distinguish between DPRX capability changes
signaled via a long HPD and via an RX_CAP_CHANGED HPD IRQ.

Both cases result in reading out the DPRX capabilities and updating the
corresponding sink and common capabilities cached in intel_dp, however
only the long HPD resets the link training/recovery state and MST link
probe parameters correspondingly. The link training/recovery state may
contain reduced maximum link rate/lane count values left over from a
previous link training failure.

Based on the above after an RX_CAP_CHANGED increased the link rate, lane
count parameters the maximum link rate/lane count in the link
training/recovery state may remain below these, leaving the newly added
valid configurations unavailable for subsequent modesets in an
inconsistent way.

Handle RX_CAP_CHANGED IRQs the same way as long HPDs and reset the link
recovery state and MST link probe parameters in that case as well.

v2: Set intel_dp::reset_link_params instead of using a helper for this.
    (Ville).

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20260522160514.2628249-2-imre.deak@intel.com