drm/i915: Allow p1 divider 2 on VLV

According to VLV2_DPLL_mphy_hsdpll_frequency_table_ww6_rev1p1.xlsm p1
can be 2-3 always.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -330,7 +330,7 @@ static const intel_limit_t intel_limits_vlv_hdmi = {
 	.m1 = { .min = 2, .max = 3 },
 	.m2 = { .min = 11, .max = 156 },
 	.p = { .min = 10, .max = 30 },
-	.p1 = { .min = 3, .max = 3 },
+	.p1 = { .min = 2, .max = 3 },
 	.p2 = { .dot_limit = 270000,
 		.p2_slow = 2, .p2_fast = 20 },
 };