SDL: Document passing -1 to clear the player index for a controller

SDL Commits
1 
From aad2df7f0d140448c0bc729600dbcd54bffb976b Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Tue, 9 Aug 2022 08:47:49 -0700
Subject: [PATCH] Document passing -1 to clear the player index for a
 controller

---
 include/SDL_gamecontroller.h | 2 +-
 include/SDL_joystick.h       | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/SDL_gamecontroller.h b/include/SDL_gamecontroller.h
index 00f08d34a71..dec675c8852 100644
--- a/include/SDL_gamecontroller.h
+++ b/include/SDL_gamecontroller.h
@@ -455,7 +455,7 @@ extern DECLSPEC int SDLCALL SDL_GameControllerGetPlayerIndex(SDL_GameController
  * Set the player index of an opened game controller.
  *
  * \param gamecontroller the game controller object to adjust.
- * \param player_index Player index to assign to this controller.
+ * \param player_index Player index to assign to this controller, or -1 to clear the player index and turn off player LEDs.
  *
  * \since This function is available since SDL 2.0.12.
  */
diff --git a/include/SDL_joystick.h b/include/SDL_joystick.h
index 60bd470f85b..69b3ccdd585 100644
--- a/include/SDL_joystick.h
+++ b/include/SDL_joystick.h
@@ -514,7 +514,7 @@ extern DECLSPEC int SDLCALL SDL_JoystickGetPlayerIndex(SDL_Joystick *joystick);
  * Set the player index of an opened joystick.
  *
  * \param joystick the SDL_Joystick obtained from SDL_JoystickOpen()
- * \param player_index the player index to set.
+ * \param player_index Player index to assign to this joystick, or -1 to clear the player index and turn off player LEDs.
  *
  * \since This function is available since SDL 2.0.12.
  */