metag/mm/cache: Restrict scope for metag_lnkget_probe

Hide symbol since it's only used within the cache.c file
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>

arch/metag/mm/cache.c

@@ -45,7 +45,7 @@ static volatile u32 lnkget_testdata[16] __initdata __aligned(64);
 
 #define LNKGET_CONSTANT 0xdeadbeef
 
-void __init metag_lnkget_probe(void)
+static void __init metag_lnkget_probe(void)
 {
 	int temp;
 	long flags;