DS GX: Fix 4-color texture coordinates

CHANGES

@@ -5,6 +5,7 @@ Bugfixes:
  - DS GX: Fix T-repeat textures (fixes mgba.io/i/577)
  - DS Video: Capture with alpha bit set
  - DS Video: Bitmap sprites use alpha bit for transparent
+ - DS GX: Fix 4-color texture coordinates
 Misc:
  - DS: Set boot complete bit in RAM on boot (fixes mgba.io/i/576, mgba.io/i/580, mgba.io/i/586)
 

src/ds/gx/software.c

@@ -152,7 +152,7 @@ static color_t _lookupColor(struct DSGXSoftwareRenderer* renderer, struct DSGXSo
 	case 2:
 		texel = ((uint8_t*) poly->texBase)[texelCoord >> 2];
 		if (texelCoord & 0x3) {
-			texel >>= 2 * texel & 3;
+			texel >>= 2 * (texelCoord & 0x3);
 		}
 		texel &= 0x3;
 		break;