drm/edid: Make sure the CEA mode arrays have the correct amount of modes

We depend on a specific relationship between the VIC number and the
index in the CEA mode arrays. Assert that the arrays have the expected
size to make sure we've not accidentally left holes in them.

v2: Pimp the BUILD_BUG_ON()s
v3: Fix typos (Manasi)

Cc: Hans Verkuil <hansverk@cisco.com>
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Reviewed-by: Thomas Anderson <thomasanderson@google.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191213174348.27261-5-ville.syrjala@linux.intel.com

drivers/gpu/drm/drm_edid.c

@@ -3213,6 +3213,9 @@ static u8 *drm_find_cea_extension(const struct edid *edid)
 
 static const struct drm_display_mode *cea_mode_for_vic(u8 vic)
 {
+	BUILD_BUG_ON(1 + ARRAY_SIZE(edid_cea_modes_1) - 1 != 127);
+	BUILD_BUG_ON(193 + ARRAY_SIZE(edid_cea_modes_193) - 1 != 219);
+
 	if (vic >= 1 && vic < 1 + ARRAY_SIZE(edid_cea_modes_1))
 		return &edid_cea_modes_1[vic - 1];
 	if (vic >= 193 && vic < 193 + ARRAY_SIZE(edid_cea_modes_193))