drm/i915: Don't pass stack garbage to pcode in the second data register

Zero initialize val2 so that we don't pass stack garbage to
the pcode qgv read command. I suspect in this case pcode
just ignores the initial value in that registers, but better
safe than sorry.

Cc: Dan Carpenter <dan.carpenter@oracle.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190710134937.25835-1-ville.syrjala@linux.intel.comReviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/display/intel_bw.c

@@ -65,7 +65,7 @@ static int icl_pcode_read_qgv_point_info(struct drm_i915_private *dev_priv,
 					 struct intel_qgv_point *sp,
 					 int point)
 {
-	u32 val = 0, val2;
+	u32 val = 0, val2 = 0;
 	int ret;
 
 	ret = sandybridge_pcode_read(dev_priv,