minui: add BOARD_USE_CUSTOM_RECOVERY_FONT

we want to use it in charger

Change-Id: I3e0288b074bd7203214d218aaee69cb4798e9531
diff --git a/minui/graphics.c b/minui/graphics.c
index 3713f61..cce02a9 100644
--- a/minui/graphics.c
+++ b/minui/graphics.c
@@ -31,7 +31,12 @@
 
 #include <pixelflinger/pixelflinger.h>
 
+#ifdef BOARD_USE_CUSTOM_RECOVERY_FONT
+#include BOARD_USE_CUSTOM_RECOVERY_FONT
+#else
 #include "font_10x18.h"
+#endif
+
 #include "minui.h"
 
 #if defined(RECOVERY_BGRA)