drm/i915/display: add I915 conditional build to intel_pch_refclk.h

Add stubs for !I915.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/4359b34cbcff6199b5e42b5311c815aa6f4a167c.1694514689.git.jani.nikula@intel.com

drm/i915: Feed the DPLL output freq back into crtc_state

Fill port_clock and hw.adjusted_mode.crtc_clock with the actual
frequency we're going to be getting from the hardware. This will
let us accurately compute all derived state that depends on those.

v2: Reintroduce iCLKIP WARN
v3: Try to deal with VLV/BXT DSI PLL as well

Reviewed-by: Jani Nikula <jani.nikula@intel.com> #v1
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220907091057.11572-8-ville.syrjala@linux.intel.com

drm/i915: Move PCH refclock stuff into its own file

Move the PCH refclk stuff (including all the LPT/WPT
iCLKIP/CLKOUT_DP things) to its own file.

We also suck in the mPHY programming from intel_fdi.c
since we're the only caller.

Cc: Dave Airlie <airlied@redhat.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211015071625.593-2-ville.syrjala@linux.intel.com
Reviewed-by: Dave Airlie <airlied@redhat.com>