pwm: tiehrpwm: Staticize non-exported symbols

Both ehrpwm_pwm_save_context() and ehrpwm_pwm_restore_context() are only used in
this file, make them static.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c
index d058ba9..6a21759 100644
--- a/drivers/pwm/pwm-tiehrpwm.c
+++ b/drivers/pwm/pwm-tiehrpwm.c
@@ -533,7 +533,7 @@
 	return pwmchip_remove(&pc->chip);
 }
 
-void ehrpwm_pwm_save_context(struct ehrpwm_pwm_chip *pc)
+static void ehrpwm_pwm_save_context(struct ehrpwm_pwm_chip *pc)
 {
 	pm_runtime_get_sync(pc->chip.dev);
 	pc->ctx.tbctl = ehrpwm_read(pc->mmio_base, TBCTL);
@@ -547,7 +547,7 @@
 	pm_runtime_put_sync(pc->chip.dev);
 }
 
-void ehrpwm_pwm_restore_context(struct ehrpwm_pwm_chip *pc)
+static void ehrpwm_pwm_restore_context(struct ehrpwm_pwm_chip *pc)
 {
 	ehrpwm_write(pc->mmio_base, TBPRD, pc->ctx.tbprd);
 	ehrpwm_write(pc->mmio_base, CMPA, pc->ctx.cmpa);