ports/doom: Use SDL2 instead of our own frontend

This allows doom to play sounds!

ports/doom/patches/0001-add-support-for-custom-SDL-path.patch

@@ -0,0 +1,27 @@
+From a4e6b807885a7cb4a507b4e114743aa0004376ad Mon Sep 17 00:00:00 2001
+From: Oskari Alaranta <oskari.alaranta@bananymous.com>
+Date: Sun, 10 Aug 2025 01:57:38 +0300
+Subject: [PATCH] add support for custom SDL path
+
+---
+ doomgeneric/Makefile.sdl | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/doomgeneric/Makefile.sdl b/doomgeneric/Makefile.sdl
+index 38402da..8c2f84e 100644
+--- a/doomgeneric/Makefile.sdl
++++ b/doomgeneric/Makefile.sdl
+@@ -12,8 +12,8 @@ else
+ endif
+ 
+ 
+-SDL_CFLAGS = `sdl2-config --cflags`
+-SDL_LIBS = `sdl2-config --cflags --libs` -lSDL2_mixer
++SDL_CFLAGS = `$(SDL_PATH)sdl2-config --cflags`
++SDL_LIBS = `$(SDL_PATH)sdl2-config --cflags --libs` -lSDL2_mixer
+ 
+ 
+ CC=clang  # gcc or g++
+-- 
+2.50.1
+