ubb-vga: test image now shows detailed horizontal and vertical timing

- ubb-vga.c (CYCLES), ubb-vga.h: corrected conversion and moved to
  ubb-vga.h
- tstimg.c (printc): added characters '=' and '+'
- tstimg.c (tstimg): print detailed horizontal and vertical timing

ubb-vga/ubb-vga.h

@@ -41,6 +41,9 @@ extern const struct mode *mode;
 void *map(off_t addr, size_t size);
 
 
+#define	CYCLES(cy)	((cy)/112.0)
+
+
 /* ccube.c */
 
 uint8_t ccube_map(uint8_t r, uint8_t g, uint8_t b);