SDL_mixer: CMakeLists.txt: expose include directory as target_include_directories

SDL Commits
1 
From 20433729fb318f7b6f773a42ffa410114cb067f2 Mon Sep 17 00:00:00 2001
From: kichikuou <[EMAIL REDACTED]>
Date: Sun, 21 Feb 2021 22:56:27 +0900
Subject: [PATCH] CMakeLists.txt: expose include directory as
 target_include_directories

So that users of this target can write "#include <SDL_mixer.h>" instead
of "#include <include/SDL_mixer.h>".
---
 CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index ce44e1b..09e7045 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -62,7 +62,7 @@ if (ANDROID)
         target_link_libraries(SDL2_mixer PRIVATE timidity)
     endif()
 
-    target_include_directories(SDL2_mixer PUBLIC .)
+    target_include_directories(SDL2_mixer PUBLIC include)
     target_link_libraries(SDL2_mixer PRIVATE SDL2)
 else()