drm/i915/display: Wait for PHY readiness not needed for disabling sequence

When going through the disconnection flow we don't need to wait for PHY
readiness and hence we can skip the wait part. For disabling the function
returns false as an indicator that the power is not enabled. After all,
we are not even using the return value when Type-C is disconnecting.

v2: Cleanup for increased readibility (Imre)

BSpec: 65380

For VLK-53734

Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231212115130.485911-1-mika.kahola@intel.com