LibGfx: Add FourCC::from_u32()

Userland/Libraries/LibGfx/FourCC.h

@@ -21,6 +21,16 @@ struct [[gnu::packed]] FourCC {
         cc[3] = name[3];
     }
 
+    static constexpr FourCC from_u32(u32 value)
+    {
+        FourCC result;
+        result.cc[0] = static_cast<char>(value >> 24);
+        result.cc[1] = static_cast<char>(value >> 16);
+        result.cc[2] = static_cast<char>(value >> 8);
+        result.cc[3] = static_cast<char>(value);
+        return result;
+    }
+
     bool operator==(FourCC const&) const = default;
     bool operator!=(FourCC const&) const = default;