arm64: compat: Enable bpf syscall

Following the arm32 commit 2d605a302972 (ARM: enable bpf syscall), wire
this syscall for arm64 compat as well.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/include/asm/unistd32.h

@@ -792,3 +792,5 @@ __SYSCALL(__NR_renameat2, sys_renameat2)
 __SYSCALL(__NR_getrandom, sys_getrandom)
 #define __NR_memfd_create 385
 __SYSCALL(__NR_memfd_create, sys_memfd_create)
+#define __NR_bpf 386
+__SYSCALL(__NR_bpf, sys_bpf)