PM / AVS: SmartReflex: fix driver name

DRIVER_NAME was undefined for SmartReflex. Now it is
defined with valid value "smartreflex". It is needed
to define proper value for:
MODULE_ALIAS("platform:" DRIVER_NAME);

Signed-off-by: Andrii Tseglytskyi <andrii.tseglytskyi@ti.com>
Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>