powerpc/kprobes: Blacklist common exception handlers

Blacklist all the exception common/OOL handlers as the kernel stack is not yet
setup, which means we can't take a trap at this point.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/head-64.h

@@ -213,6 +213,7 @@ end_##sname:
 	USE_TEXT_SECTION();					\
 	.balign IFETCH_ALIGN_BYTES;				\
 	.global name;						\
+	_ASM_NOKPROBE_SYMBOL(name);				\
 	DEFINE_FIXED_SYMBOL(name);				\
 name: