Limit saturation for RGB_MATRIX_JELLYBEAN_RAINDROPS (#12669)

* Set saturation limit to jellybean_raindrops_anim.h

* Use faster bit-shift maths and qadd8

* Remove extra parenthesis

* Single bitmask operation is sufficient.

Co-authored-by: filterpaper <filterpaper@localhost>

quantum/rgb_matrix_animations/jellybean_raindrops_anim.h

@@ -4,7 +4,7 @@ RGB_MATRIX_EFFECT(JELLYBEAN_RAINDROPS)
 
 static void jellybean_raindrops_set_color(int i, effect_params_t* params) {
     if (!HAS_ANY_FLAGS(g_led_config.flags[i], params->flags)) return;
-    HSV hsv = {rand() & 0xFF, rand() & 0xFF, rgb_matrix_config.hsv.v};
+    HSV hsv = {rand() & 0xFF, qadd8(rand() & 0x7F, 0x80), rgb_matrix_config.hsv.v};
     RGB rgb = rgb_matrix_hsv_to_rgb(hsv);
     rgb_matrix_set_color(i, rgb.r, rgb.g, rgb.b);
 }