arm64 BTI support for mpg123

This port has some infrastructure to use an optimized function that
uses a function pointer. Not sure why for arm64 it actually uses that
infrastructure, since the only alternative is the generic C
implementation. But adding a BTI instruction is the easiest fix.

ok?


Index: audio/mpg123/Makefile
===================================================================
RCS file: /cvs/ports/audio/mpg123/Makefile,v
retrieving revision 1.116
diff -u -p -r1.116 Makefile
--- audio/mpg123/Makefile 30 Mar 2023 12:35:39 -0000 1.116
+++ audio/mpg123/Makefile 24 Jul 2023 19:23:10 -0000
@@ -1,6 +1,7 @@
COMMENT= fast console MPEG audio player and decoder library

DISTNAME= mpg123-1.31.3
+REVISION= 0
SHARED_LIBS= mpg123 7.2 # 47.0
SHARED_LIBS+= out123 2.1 # 4.7
SHARED_LIBS+= syn123 0.1 # 1.5
Index: audio/mpg123/patches/patch-src_libmpg123_dct36_neon64_S
===================================================================
RCS file: audio/mpg123/patches/patch-src_libmpg123_dct36_neon64_S
diff -N audio/mpg123/patches/patch-src_libmpg123_dct36_neon64_S
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ audio/mpg123/patches/patch-src_libmpg123_dct36_neon64_S 24 Jul 2023 19:23:10 -0000
@@ -0,0 +1,11 @@
+Index: src/libmpg123/dct36_neon64.S
+--- src/libmpg123/dct36_neon64.S.orig
++++ src/libmpg123/dct36_neon64.S
+@@ -49,6 +49,7 @@ dct36_aarch64_COS9:
+ .type ASM_NAME(dct36_neon64), %function
+