sparc: fix sparse warning in kernel/pmc.c

Fix following warning:
arch/sparc/kernel/pmc.c:41:6: warning: symbol 'pmc_swift_idle'
was not declared. Should it be static?

It was not used outside this file - make it static

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc/kernel/pmc.c b/arch/sparc/kernel/pmc.c
index 2afcfab..33cd499 100644
--- a/arch/sparc/kernel/pmc.c
+++ b/arch/sparc/kernel/pmc.c
@@ -38,7 +38,7 @@
  * CPU idle callback function
  * See .../arch/sparc/kernel/process.c
  */
-void pmc_swift_idle(void)
+static void pmc_swift_idle(void)
 {
 #ifdef PMC_DEBUG_LED
 	set_auxio(0x00, AUXIO_LED);