linux-imx

PM / Domains: Move the Subdomain check into _genpd_power_off

Move the Subdomain check into _genpd_power_off, then the caller does
not have to check it each time. This also ensures a double check
of &genpd->sd_count before really power off domain in case it's
increased asychronously by subdomains. This is the same behavior
as the original genpd_power_off() does.

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>