drm/i915: factor out intel_lvds_get_edid()

Corresponding to

  intel_crt_get_edid()
  intel_sdvo_get_edid()
  intel_dp_get_edid()

add a intel_lvds_get_edid(). We plan to call this during a
switcheroo-reprobe in later patches.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andreas Heider <andreas@meetr.de>
Cc: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
drm/i915: change intel_sdvo_get_edid() prototype

In future patches, we intend to introduce a generic interface to the
various get_edid() functions. All the other get_edid() functions accept
two arguments: a struct drm_connector *, and a struct i2c_adapter *. So,
introduce a second dummy variable in intel_sdvo_get_edid().

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andreas Heider <andreas@meetr.de>
Cc: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
drm/i915: introduce intel_connector->reprobe

Introduce a struct edid *(*reprobe)(struct drm_connector *, struct
i2c_adapter *) in struct intel_connector to point to various get_edid()
functions.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andreas Heider <andreas@meetr.de>
Cc: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>