android: use __ARM_NEON instead of __ARM_NEON__ to include <arm_neon.h>

Only __ARM_NEON is defined with Android NDK and arm64-v8a
Tested on ndk-r18, ndk-r13 and also Xcode.
(Visual Studio needs a different fix).

Fixes Bugzilla #4409.
diff --git a/include/SDL_cpuinfo.h b/include/SDL_cpuinfo.h
index ac8263a..bbd66db 100644
--- a/include/SDL_cpuinfo.h
+++ b/include/SDL_cpuinfo.h
@@ -54,7 +54,7 @@
 #if defined(HAVE_ALTIVEC_H) && defined(__ALTIVEC__) && !defined(__APPLE_ALTIVEC__) && defined(SDL_ENABLE_ALTIVEC_H)
 #include <altivec.h>
 #endif
-#if defined(__ARM_NEON__) && !defined(SDL_DISABLE_ARM_NEON_H)
+#if defined(__ARM_NEON) && !defined(SDL_DISABLE_ARM_NEON_H)
 #include <arm_neon.h>
 #endif
 #if defined(__3dNOW__) && !defined(SDL_DISABLE_MM3DNOW_H)
diff --git a/src/audio/SDL_audiotypecvt.c b/src/audio/SDL_audiotypecvt.c
index 5f8cc22..22f4b71 100644
--- a/src/audio/SDL_audiotypecvt.c
+++ b/src/audio/SDL_audiotypecvt.c
@@ -26,7 +26,7 @@
 #include "SDL_assert.h"
 
 /* !!! FIXME: disabled until we fix https://bugzilla.libsdl.org/show_bug.cgi?id=4186 */
-#if 0 /*def __ARM_NEON__*/
+#if 0 /*def __ARM_NEON */
 #define HAVE_NEON_INTRINSICS 1
 #endif