powerpc/fsl-booke: declare tlbcam_index for use in c

So, KVM needs to read tlbcam_index to know exactly
which TLB1 entry is unused by host.

Signed-off-by: Liu Yu <yu.liu@freescale.com>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/powerpc/include/asm/mmu-fsl-booke.h

@@ -75,6 +75,8 @@
 
 #ifndef __ASSEMBLY__
 
+extern unsigned int tlbcam_index;
+
 typedef struct {
 	unsigned int	id;
 	unsigned int	active;