*/linux-rl9-sdl*: add SDL[2] packages from Rocky Linux 9/EPEL9 (+)

Added ports:

devel/linux-rl9-sdl12 -- SDL1 compat library
devel/linux-rl9-sdl20 -- SDL2 core library

audio/linux-rl9-sdl_sound -- SDL1 sound library
audio/linux-rl9-sdl2_mixer -- SDL2 mixer and library
graphics/linux-rl9-sdl_gfx -- SDL1 GFX library
graphics/linux-rl9-sdl_image -- SDL1 image library
graphics/linux-rl9-sdl_ttf -- SDL1 TTF library
graphics/linux-rl9-sdl2_gfx -- SDL2 GFX library
graphics/linux-rl9-sdl2_image -- SDL2 image library
graphics/linux-rl9-sdl2_ttf -- SDL2 TTF library
net/linux-rl9-sdl_net -- SDL1 network library
net/linux-rl9-sdl2_net -- SDL2 network library

Sponsored by: Future Crew, LLC