ARM: OMAP2+: do not export am43xx_control functions

Do not export am43xx_control_{save,restore}_context to avoid
the foloowing warnings:

arch/arm/mach-omap2/control.c:687:6: warning: symbol 'am43xx_control_save_context' was not declared. Should it be static?
arch/arm/mach-omap2/control.c:701:6: warning: symbol 'am43xx_control_restore_context' was not declared. Should it be static?
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/control.c

@@ -684,7 +684,7 @@ static u32 am33xx_control_vals[ARRAY_SIZE(am43xx_control_reg_offsets)];
  *
  * Save the wkup domain registers
  */
-void am43xx_control_save_context(void)
+static void am43xx_control_save_context(void)
 {
 	int i;
 
@@ -698,7 +698,7 @@ void am43xx_control_save_context(void)
  *
  * Restore the wkup domain registers
  */
-void am43xx_control_restore_context(void)
+static void am43xx_control_restore_context(void)
 {
 	int i;