Export powerpc CPU features for auxvec

FreeBSD exports the AT_HWCAP* auxvec items if provided by the ELF sysentvec
structure.  Add the CPU features to be exported, so user space can more
easily check for them without using the hw.cpu_features and hw.cpu_features2
sysctls.

sys/powerpc/powerpc/elf32_machdep.c

@@ -123,6 +123,8 @@ struct sysentvec elf32_freebsd_sysvec = {
 	.sv_schedtail	= NULL,
 	.sv_thread_detach = NULL,
 	.sv_trap	= NULL,
+	.sv_hwcap	= &cpu_features,
+	.sv_hwcap2	= &cpu_features2,
 };
 INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec);
 

sys/powerpc/powerpc/elf64_machdep.c

@@ -88,6 +88,8 @@ struct sysentvec elf64_freebsd_sysvec_v1 = {
 	.sv_schedtail	= NULL,
 	.sv_thread_detach = NULL,
 	.sv_trap	= NULL,
+	.sv_hwcap	= &cpu_features,
+	.sv_hwcap2	= &cpu_features2,
 };
 INIT_SYSENTVEC(elf64_sysvec_v1, &elf64_freebsd_sysvec_v1);