The recent introduction of reset control in pwrseq_simple introduced
a regression for platforms without RESET_CONTROLLER support, because
devm_reset_control_get_optional_shared() would return NULL and make all
resets no-ops. Instead of enforcing this dependency, rely on this behavior
to determine reset support. As a benefit we can get the rid of the
use_reset flag.
Fixes: 73bf4b7381f7 ("mmc: pwrseq_simple: add support for one reset control")
Signed-off-by: Stefan Wahren <wahrenst@xxxxxxx>