Add Steam Controller mapping (#15601)

Also fixed Hori QAM button mapping

(cherry picked from commit c00d7b4bf5580462924de5794da50a98fce09b2c)

src/joystick/SDL_gamepad.c

@@ -1253,7 +1253,7 @@ static GamepadMapping_t *SDL_CreateMappingForHIDAPIGamepad(SDL_GUID guid)
             SDL_strlcat(mapping_string, "paddle1:b11,paddle2:b12,", sizeof(mapping_string));
         } else if (SDL_IsJoystickSteamTriton(vendor, product)) {
             // Second generation Steam controllers have 4 back paddle buttons
-            SDL_strlcat(mapping_string, "misc1:b11,paddle1:b12,paddle2:b13,paddle3:b14,paddle4:b15", sizeof(mapping_string));
+            SDL_strlcat(mapping_string, "misc1:b11,paddle1:b12,paddle2:b13,paddle3:b14,paddle4:b15,touchpad:b17,misc2:b16,misc3:b19,misc4:b18,misc5:b21,misc6:b20", sizeof(mapping_string));
         } else if (SDL_IsJoystickNintendoSwitchPro(vendor, product) ||
                    SDL_IsJoystickNintendoSwitchProInputOnly(vendor, product)) {
             // Nintendo Switch Pro controllers have a screenshot button
@@ -1277,7 +1277,7 @@ static GamepadMapping_t *SDL_CreateMappingForHIDAPIGamepad(SDL_GUID guid)
             }
         } else if (SDL_IsJoystickHoriSteamController(vendor, product)) {
             /* The Wireless HORIPad for Steam has QAM, Steam, Capsense L/R Sticks, 2 rear buttons, and 2 misc buttons */
-            SDL_strlcat(mapping_string, "paddle1:b13,paddle2:b12,paddle3:b15,paddle4:b14,misc2:b11,misc3:b16,misc4:b17", sizeof(mapping_string));
+            SDL_strlcat(mapping_string, "paddle1:b13,paddle2:b12,paddle3:b15,paddle4:b14,misc1:b11,misc3:b16,misc4:b17", sizeof(mapping_string));
         } else if (SDL_IsJoystickFlydigiController(vendor, product)) {
             SDL_strlcat(mapping_string, "paddle1:b11,paddle2:b12,paddle3:b13,paddle4:b14,", sizeof(mapping_string));
             if (guid.data[15] >= SDL_FLYDIGI_VADER2) {