powerpc: Use linux/thread_info.h in processor.h

When we enable THREAD_INFO_IN_TASK we will remove our definition of
current_thread_info(). Instead it will come from linux/thread_info.h

So switch processor.h to include the latter, so that it can continue
to find current_thread_info().
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Split out of larger patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/processor.h

@@ -40,7 +40,7 @@
 
 #ifndef __ASSEMBLY__
 #include <linux/types.h>
-#include <asm/thread_info.h>
+#include <linux/thread_info.h>
 #include <asm/ptrace.h>
 #include <asm/hw_breakpoint.h>