link: Reset fan target RPM when suspending

This prevents the fan from coming on loudly during resume.

BUG=chrome-os-partner:15187
BRANCH=link
TEST=manual

- power on system
- wait for it to heat up; type faninfo periodically from ec console
- when faninfo reports non-zero, type 'powerd_suspend' at root shell
- faninfo should now report Target: 0 rpm Enable: no

Change-Id: Ia5ee93c0f5c6626afd54a22d2996ab65cf8e3b18
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/35303
Reviewed-by: Bill Richardson <wfrichar@chromium.org>

chip/lm4/pwm.c

@@ -391,6 +391,7 @@ DECLARE_HOOK(HOOK_CHIPSET_RESUME, pwm_resume, HOOK_PRIO_DEFAULT);
 static int pwm_suspend(void)
 {
 	pwm_enable_fan(0);
+	pwm_set_fan_target_rpm(0);
 	pwm_set_keyboard_backlight(0);
 	return EC_SUCCESS;
 }