SDL: add support for libsamplerate's "linear" resampling mode

SDL Commits
1 
From 8efa1f8fc60e0a2961ce3bad9293c048301d25ba Mon Sep 17 00:00:00 2001
From: Fabian Greffrath <[EMAIL REDACTED]>
Date: Mon, 16 Jan 2023 15:17:26 +0100
Subject: [PATCH] add support for libsamplerate's "linear" resampling mode

Fixes #6998
---
 src/audio/SDL_audio.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/audio/SDL_audio.c b/src/audio/SDL_audio.c
index d42396de5b61..46ea9fa9bb14 100644
--- a/src/audio/SDL_audio.c
+++ b/src/audio/SDL_audio.c
@@ -160,6 +160,8 @@ static SDL_bool LoadLibSampleRate(void)
         SRC_converter = SRC_SINC_MEDIUM_QUALITY;
     } else if (*hint == '3' || SDL_strcasecmp(hint, "best") == 0) {
         SRC_converter = SRC_SINC_BEST_QUALITY;
+    } else if (*hint == '4' || SDL_strcasecmp(hint, "linear") == 0) {
+        SRC_converter = SRC_LINEAR;
     } else {
         return SDL_FALSE; /* treat it like "default", don't load anything. */
     }