Fix for color grading always appearing monochrome on Vita

Fixed ApplyCommonGradingSteps for PSP2, the PSP2 cg compiler was using the incorrect version of max(), passing a float as the first parameter caused it to use the single component version of max instead of up-casting to float3 as happens on other platforms, it looks like PSP2 cg is missing the required overload for this function, explicitly casting the first parameter to float3 fixes this.

Author: PaulDunning

PostProcessing/Shaders/Builtins/Lut2DBaker.shader

@@ -42,7 +42,7 @@ Shader "Hidden/PostProcessing/Lut2DBaker"
             colorLinear = LiftGammaGainHDR(colorLinear, _Lift, _InvGamma, _Gain);
 
             // Do NOT feed negative values to RgbToHsv or they'll wrap around
-            colorLinear = max(0.0, colorLinear);
+            colorLinear = max((float3)0.0, colorLinear);
 
             float3 hsv = RgbToHsv(colorLinear);