gma500: Fix n, m1 and m2 clock limits for sdvo and lvds

The values of n, m1 and m2 needs to be subtracted by 2 before writing them to
the FP register. The dot clock calculation already thinks of these values in
register form so we must also specify them as such.
Signed-off-by: NPatrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

drivers/gpu/drm/gma500/psb_intel_display.c

@@ -85,14 +85,14 @@ struct psb_intel_limit_t {
 #define I9XX_DOT_MAX		 400000
 #define I9XX_VCO_MIN		1400000
 #define I9XX_VCO_MAX		2800000
-#define I9XX_N_MIN		      3
-#define I9XX_N_MAX		      8
+#define I9XX_N_MIN		      1
+#define I9XX_N_MAX		      6
 #define I9XX_M_MIN		     70
 #define I9XX_M_MAX		    120
-#define I9XX_M1_MIN		     10
-#define I9XX_M1_MAX		     20
-#define I9XX_M2_MIN		      5
-#define I9XX_M2_MAX		      9
+#define I9XX_M1_MIN		      8
+#define I9XX_M1_MAX		     18
+#define I9XX_M2_MIN		      3
+#define I9XX_M2_MAX		      7
 #define I9XX_P_SDVO_DAC_MIN	      5
 #define I9XX_P_SDVO_DAC_MAX	     80
 #define I9XX_P_LVDS_MIN		      7