audio/sfizz: fix build on powerpc*

ori 0,0,0 is nop instruction on powerpc*
Additional headers are necessary:
In file included from /wrkdirs/usr/ports/audio/sfizz/work/sfizz-0.4.0/external/abseil-cpp/absl/base/internal/unscaledcycleclock.cc:27:
/usr/include/sys/sysctl.h:1185:25: error: unknown type name 'u_int'
int     sysctl(const int *, u_int, void *, size_t *, const void *, size_t);
                            ^
/wrkdirs/usr/ports/audio/sfizz/work/sfizz-0.4.0/external/abseil-cpp/absl/base/internal/unscaledcycleclock.cc:91:10: error: unknown type name 'once_flag'
  static once_flag init_timebase_frequency_once;
         ^
/wrkdirs/usr/ports/audio/sfizz/work/sfizz-0.4.0/external/abseil-cpp/absl/base/internal/unscaledcycleclock.cc:93:18: error: no member named 'LowLevelCallOnce' in namespace 'absl::lts_2020_02_25::base_internal'
  base_internal::LowLevelCallOnce(&init_timebase_frequency_once, [&]() {

audio/sfizz/files/patch-external_abseil-cpp_absl_base_internal_unscaledcycleclock.cc

@@ -0,0 +1,14 @@
+--- external/abseil-cpp/absl/base/internal/unscaledcycleclock.cc.orig	2021-06-16 13:17:13 UTC
++++ external/abseil-cpp/absl/base/internal/unscaledcycleclock.cc
+@@ -24,8 +24,10 @@
+ #ifdef __GLIBC__
+ #include <sys/platform/ppc.h>
+ #elif defined(__FreeBSD__)
+-#include <sys/sysctl.h>
++#include "absl/base/call_once.h"
+ #include <sys/types.h>
++#include <sys/sysctl.h>
++#include <threads.h>
+ #endif
+ #endif
+

audio/sfizz/files/patch-src_external_atomic__queue_defs.h

@@ -1,4 +1,4 @@
---- src/external/atomic_queue/defs.h.orig	2020-04-20 01:14:22 UTC
+--- src/external/atomic_queue/defs.h.orig	2020-07-23 22:01:34 UTC
 +++ src/external/atomic_queue/defs.h
 @@ -6,11 +6,15 @@
 
@@ -26,3 +26,14 @@
  static inline void spin_loop_pause() noexcept {
  #if (defined(__ARM_ARCH_6K__) || \
       defined(__ARM_ARCH_6Z__) || \
+@@ -37,6 +41,10 @@ static inline void spin_loop_pause() noexcept {
+ #endif
+ }
+ } // namespace atomic_queue
++#elif defined(__powerpc__)
++static inline void spin_loop_pause() noexcept {
++    asm volatile("ori 0,0,0" ::: "memory");
++}
+ #else
+ #error "Unknown CPU architecture."
+ #endif