sdl: Add a patch to fix events received when in the deadzone
opendingux: GCW0: Make SDL2 detect the linkdev device as keyboard

Instead of detecting gpio-keys, which is reserved for pwswd.
Otherwise, when the "joystick mode" of linkdev is activated, SDL2 will
receive both keyboard events and joystick events.
Revert "sdl: Add a config option to disable the Linux input event interface"

This re-enables evdev support for SDL, as SDL has been fixed to work
correctly with evdev, and joydev has been disactivated in the kernel.

This reverts commit 47ea88306ea57ab734fe92a79cfce02a53f95f7b.