drm/i915: base gmbus pin validity check on the gmbus pin map array

This will be helpful for adding future platforms. It is better to keep
the information in the single point of truth (the table) instead of
duplicating it into the validity function.

While at it, add dev_priv parameter to the function, also to prepare for
adding future platform support.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 0ad11d9..d63997b 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3064,10 +3064,8 @@
 /* intel_i2c.c */
 extern int intel_setup_gmbus(struct drm_device *dev);
 extern void intel_teardown_gmbus(struct drm_device *dev);
-static inline bool intel_gmbus_is_valid_pin(unsigned int pin)
-{
-	return (pin >= GMBUS_PIN_SSC && pin <= GMBUS_PIN_DPD);
-}
+extern bool intel_gmbus_is_valid_pin(struct drm_i915_private *dev_priv,
+				     unsigned int pin);
 
 extern struct i2c_adapter *
 intel_gmbus_get_adapter(struct drm_i915_private *dev_priv, unsigned int pin);