Add Steam Deck controller mapping to database.

This adds support for the back paddles, and the "..." key
which are not automatically detected.
* "Back" is mapped to the top left "two windows" key.
* "Start" is mapped to the top right "hambuger menu" key.
* "Guide" is mapped to the "Steam" key.
* The "..." key is just a generic button.

When looking at the screen, paddles are number
* P1: Top right
* P2: Top left
* P3: Bottom right
* P4: Botom Left

The new controller mapping was created with the SDL3 gamepadmap tool.

src/joystick/SDL_gamepad_db.h

@@ -815,6 +815,7 @@ static const char *s_GamepadMappings[] = {
     "05000000de2800000212000001000000,Steam Controller,a:b0,b:b1,back:b6,dpdown:b14,dpleft:b15,dpright:b13,dpup:b12,guide:b8,leftshoulder:b4,leftstick:b9,lefttrigger:a2,leftx:a0,lefty:a1,paddle1:b11,paddle2:b10,rightshoulder:b5,righttrigger:a3,start:b7,x:b2,y:b3,",
     "05000000de2800000511000001000000,Steam Controller,a:b0,b:b1,back:b6,dpdown:b14,dpleft:b15,dpright:b13,dpup:b12,guide:b8,leftshoulder:b4,leftstick:b9,lefttrigger:a2,leftx:a0,lefty:a1,paddle1:b11,paddle2:b10,rightshoulder:b5,righttrigger:a3,start:b7,x:b2,y:b3,",
     "05000000de2800000611000001000000,Steam Controller,a:b0,b:b1,back:b6,dpdown:b14,dpleft:b15,dpright:b13,dpup:b12,guide:b8,leftshoulder:b4,leftstick:b9,lefttrigger:a2,leftx:a0,lefty:a1,paddle1:b11,paddle2:b10,rightshoulder:b5,righttrigger:a3,start:b7,x:b2,y:b3,",
+    "03000000de2800000512000011010000,Steam Deck,platform:Linux,crc:17f6,a:b3,b:b4,x:b5,y:b6,back:b11,guide:b13,start:b12,leftstick:b14,rightstick:b15,leftshoulder:b7,rightshoulder:b8,dpup:b16,dpdown:b17,dpleft:b18,dpright:b19,misc1:b2,paddle1:b21,paddle2:b20,paddle3:b23,paddle4:b22,leftx:a0,lefty:a1,rightx:a2,righty:a3,lefttrigger:a9,righttrigger:a8,",
     "03000000de280000ff11000001000000,Steam Virtual Gamepad,a:b0,b:b1,back:b6,dpdown:h0.4,dpleft:h0.8,dpright:h0.2,dpup:h0.1,guide:b8,leftshoulder:b4,leftstick:b9,lefttrigger:a2,leftx:a0,lefty:a1,rightshoulder:b5,rightstick:b10,righttrigger:a5,rightx:a3,righty:a4,start:b7,x:b2,y:b3,",
     "0500000011010000311400001b010000,SteelSeries Stratus Duo,a:b0,b:b1,back:b10,dpdown:h0.4,dpleft:h0.8,dpright:h0.2,dpup:h0.1,guide:b32,leftshoulder:b6,leftstick:b13,lefttrigger:a5,leftx:a0,lefty:a1,rightshoulder:b7,rightstick:b14,righttrigger:a4,rightx:a2,righty:a3,start:b11,x:b3,y:b4,",
     "05000000110100001914000009010000,SteelSeries Stratus XL,a:b0,b:b1,back:b17,dpdown:h0.4,dpleft:h0.8,dpright:h0.2,dpup:h0.1,guide:b18,leftshoulder:b6,leftstick:b13,lefttrigger:+a5,leftx:a0,lefty:a1,rightshoulder:b7,rightstick:b14,righttrigger:+a4,rightx:a2,righty:a3,start:b11,x:b3,y:b4,",