drm/i915/dpio: have chv_data_lane_soft_reset() get/put dpio internally

Have chv_data_lane_soft_reset() get/put dpio internally, and use a
locked version of it within intel_dpio_phy.c. This drops the dependency
on vlv sideband from g4x_dp.c and g4x_hdmi.c, and makes that a DPIO PHY
implementation detail.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://lore.kernel.org/r/20250411102715.613082-1-jani.nikula@intel.com


Signed-off-by: Jani Nikula <jani.nikula@intel.com>