sdl12-compat: dr_mp3.h: fix ARM64 builds with MSVC.

SDL Commits
1 
From 2cca65787edb5b45cedc6ccbfa5104f95e91d16c Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Sun, 10 Apr 2022 04:10:28 +0300
Subject: [PATCH] dr_mp3.h: fix ARM64 builds with MSVC.

Fixes: https://github.com/icculus/SDL_sound/issues/58
See: https://github.com/mackron/dr_libs/issues/229
---
 src/dr_mp3.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/dr_mp3.h b/src/dr_mp3.h
index 1c8198d..52609bb 100644
--- a/src/dr_mp3.h
+++ b/src/dr_mp3.h
@@ -2117,7 +2117,7 @@ static void drmp3d_synth(float *xl, drmp3d_sample_t *dstl, int nch, float *lins)
             vst1_lane_s16(dstl + (49 + i)*nch, pcmb, 2);
 #endif
 #else
-            static const drmp3_f4 g_scale = { 1.0f/32768.0f, 1.0f/32768.0f, 1.0f/32768.0f, 1.0f/32768.0f };
+            const drmp3_f4 g_scale = vdupq_n_f32(1.0f/32768.0f);
             a = DRMP3_VMUL(a, g_scale);
             b = DRMP3_VMUL(b, g_scale);
 #if DRMP3_HAVE_SSE