sdl2: Update to version 2.26.2

sdl2: Update to version 2.26.2

- Update from version 2.26.0 to 2.26.2
- Update of rootfile
- Changelog
    2.26.2 Latest
	This is a stable bugfix release, with the following changes:
	    Fixed long delay at startup when a Razer keyboard is connected
	    Fixed not receiving SDLK_5 or SDL_SCANCODE_5 when using the AZERTY keyboard
             layout on Linux
    2.26.1
	This is a stable bugfix release, with the following changes:
	    Improved audio resampling quality
	    Fixed crash if SDL_GetPointDisplayIndex() or SDL_GetRectDisplayIndex() are
             called before SDL_VideoInit()
	    Fixed building with older Xcode and macOS SDK
	    Fixed building when not using shared Wayland libraries

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>