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: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

arch/sparc/kernel/pmc.c

@@ -38,7 +38,7 @@ static u8 __iomem *regs;
  * 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);