powerpc/sparse: make some things static

This is just a smattering of things picked up by sparse that should
be made static.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/powernv/idle.c

@@ -29,7 +29,7 @@
 
 static u32 supported_cpuidle_states;
 
-int pnv_save_sprs_for_winkle(void)
+static int pnv_save_sprs_for_winkle(void)
 {
 	int cpu;
 	int rc;