powerpc/bpf/jit: Disable classic BPF JIT on ppc64le

commit 844e3be4 upstream.

Classic BPF JIT was never ported completely to work on little endian
powerpc. However, it can be enabled and will crash the system when used.
As such, disable use of BPF JIT on ppc64le.

Fixes: 7c105b63 ("powerpc: Add CONFIG_CPU_LITTLE_ENDIAN kernel config option.")
Reported-by: Thadeu Lima de Souza Cascardo <cascardo@redhat.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[bwh: Backported to 3.16: config symbol is BPF_JIT and also depends on PPC64]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

arch/powerpc/Kconfig

@@ -124,7 +124,7 @@ config PPC
 	select IRQ_FORCED_THREADING
 	select HAVE_RCU_TABLE_FREE if SMP
 	select HAVE_SYSCALL_TRACEPOINTS
-	select HAVE_BPF_JIT if PPC64
+	select HAVE_BPF_JIT if PPC64 && CPU_BIG_ENDIAN
 	select HAVE_ARCH_JUMP_LABEL
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select GENERIC_SMP_IDLE_THREAD