Fonts: Add charcount field to font_desc

Subsystems are hard-coding the number of characters of our built-in fonts
as 256. Include that information in our kernel font descriptor, `struct
font_desc`.

Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/65952296d1d9486093bd955d1536f7dcd11112c6.1605169912.git.yepeilin.cs@gmail.com
diff --git a/lib/fonts/font_6x10.c b/lib/fonts/font_6x10.c
index 6e3c4b7..e65df01 100644
--- a/lib/fonts/font_6x10.c
+++ b/lib/fonts/font_6x10.c
@@ -3083,6 +3083,7 @@ const struct font_desc font_6x10 = {
 	.name	= "6x10",
 	.width	= 6,
 	.height	= 10,
+	.charcount = 256,
 	.data	= fontdata_6x10.data,
 	.pref	= 0,
 };