ARM: OMAP2+: prm44xx: make prm_{save,restore}_context static

The prm_{save,restore}_context functions are not exported
so make them static to avoid the following warnings:

arch/arm/mach-omap2/prm44xx.c:748:6: warning: symbol 'prm_save_context' was not declared. Should it be static?
arch/arm/mach-omap2/prm44xx.c:759:6: warning: symbol 'prm_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/prm44xx.c

@@ -745,7 +745,7 @@ struct pwrdm_ops omap4_pwrdm_operations = {
 
 static int omap44xx_prm_late_init(void);
 
-void prm_save_context(void)
+static void prm_save_context(void)
 {
 	omap_prm_context.irq_enable =
 			omap4_prm_read_inst_reg(AM43XX_PRM_OCP_SOCKET_INST,
@@ -756,7 +756,7 @@ void prm_save_context(void)
 						omap4_prcm_irq_setup.pm_ctrl);
 }
 
-void prm_restore_context(void)
+static void prm_restore_context(void)
 {
 	omap4_prm_write_inst_reg(omap_prm_context.irq_enable,
 				 OMAP4430_PRM_OCP_SOCKET_INST,