graphics/libjxl: fix build on powerpc64*

Add FreeBSD variants for linux code.

The include in cpu.cc is not actually necessary, so I did not include anything for FreeBSD.

graphics/libjxl/files/patch-third__party_highway_hwy_nanobenchmark.cc

@@ -0,0 +1,30 @@
+--- third_party/highway/hwy/nanobenchmark.cc.orig	2021-09-30 15:38:30 UTC
++++ third_party/highway/hwy/nanobenchmark.cc
+@@ -47,7 +47,12 @@
+
+ #include "hwy/base.h"
+ #if HWY_ARCH_PPC
++#if linux
+ #include <sys/platform/ppc.h>  // NOLINT __ppc_get_timebase_freq
++#elif __FreeBSD__
++#include <sys/types.h>
++#include <sys/sysctl.h>                 /* must come after sys/types.h */
++#endif
+ #elif HWY_ARCH_X86
+
+ #if HWY_COMPILER_MSVC
+@@ -400,7 +405,14 @@ double NominalClockRate() {
+
+ double InvariantTicksPerSecond() {
+ #if HWY_ARCH_PPC
++#if linux
+   return __ppc_get_timebase_freq();
++#elif __FreeBSD__
++  static double cycles_per_second = 0;
++  size_t length = sizeof(cycles_per_second);
++  sysctlbyname("kern.timecounter.tc.timebase.frequency", &cycles_per_second,
++               &length, NULL, 0);
++#endif
+ #elif HWY_ARCH_X86
+   // We assume the TSC is invariant; it is on all recent Intel/AMD CPUs.
+   return NominalClockRate();

graphics/libjxl/files/patch-tools_cpu_cpu.cc

@@ -0,0 +1,13 @@
+--- tools/cpu/cpu.cc.orig	2021-09-30 15:38:45 UTC
++++ tools/cpu/cpu.cc
+@@ -19,7 +19,9 @@
+ #endif
+
+ #if JXL_ARCH_PPC
+-#include <sys/platform/ppc.h>  // __ppc_get_timebase_freq
++#if linux
++#include <sys/platform/ppc.h>  // NOLINT __ppc_get_timebase_freq
++#endif
+ #endif
+
+ #if JXL_ARCH_ARM