clk: renesas: mstp: Keep wakeup sources active during system suspend

If a device is part of the CPG/MSTP Clock Domain and to be used as a
wakeup source, it must be kept active during system suspend.

Currently this is handled in device-specific drivers by explicitly
increasing the use count of the module clock when the device is
configured as a wakeup source.  However, the proper way to prevent the
device from being stopped is to inform this requirement to the genpd
core, by setting the GENPD_FLAG_ACTIVE_WAKEUP flag.

Note that this will only affect devices configured as wakeup sources.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/clk/renesas/clk-mstp.c

@@ -341,7 +341,7 @@ void __init cpg_mstp_add_clk_domain(struct device_node *np)
 		return;
 
 	pd->name = np->name;
-	pd->flags = GENPD_FLAG_PM_CLK;
+	pd->flags = GENPD_FLAG_PM_CLK | GENPD_FLAG_ACTIVE_WAKEUP;
 	pd->attach_dev = cpg_mstp_attach_dev;
 	pd->detach_dev = cpg_mstp_detach_dev;
 	pm_genpd_init(pd, &pm_domain_always_on_gov, false);