ARM: pxa: ssp: unneeded to free devm_ allocated data

devm_ allocated data will be automatically freed. The free
of devm_ allocated data is invalid.

Fixes: 1c459de1 ("ARM: pxa: ssp: use devm_ functions")
Signed-off-by: Peng Hao <peng.hao2@zte.com.cn>
[title's prefix changed]
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>