Add 2 second pre-dim and bugfix blank timer

2 second predim code courtesy of bigbiff

Change-Id: I052ac422f78dc82c05f58c188587534b800b935a
diff --git a/minuitwrp/minui.h b/minuitwrp/minui.h
index d66807c..03e15bb 100644
--- a/minuitwrp/minui.h
+++ b/minuitwrp/minui.h
@@ -27,7 +27,7 @@
 int gr_fb_height(void);
 gr_pixel *gr_fb_data(void);
 void gr_flip(void);
-void gr_fb_blank(int blank);
+int gr_fb_blank(int blank);
 
 void gr_color(unsigned char r, unsigned char g, unsigned char b, unsigned char a);
 void gr_fill(int x, int y, int w, int h);