Ports: Fix SDL2 port trying to build against PulseAudio for some reason.

I didn't look into why, but for some reason the SDL2 cmake build system
thinks it should build against PulseAudio which we definitely don't have.
So just tell it explicitly not to do that.

Fixes #265.

Ports/.port_include.sh

@@ -68,7 +68,7 @@ run_patch() {
 }
 
 run_configure_cmake() {
-    run_command cmake -DCMAKE_TOOLCHAIN_FILE="$SERENITY_ROOT/Toolchain/CMakeToolchain.txt" .
+    run_command cmake -DCMAKE_TOOLCHAIN_FILE="$SERENITY_ROOT/Toolchain/CMakeToolchain.txt" $CMAKEOPTS .
 }
 
 run_configure_autotools() {

Ports/SDL2/SDL2.sh

@@ -4,6 +4,7 @@ fetch() {
     run_fetch_git "https://github.com/SerenityOS/SDL"
 }
 configure() {
+    CMAKEOPTS="-DPULSEAUDIO=OFF"
     run_configure_cmake
 }
 build() {