Currently this driver is missing a check on the return value of devm_kzalloc,
which would cause a NULL pointer dereference in a OOM situation.

This patch adds the aformentioned missing check.
Signed-off-by: NPeter Griffin <peter.griffin@linaro.org>
Acked-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>