media: tegra_cec: fix the return value handle for platform_get_irq()

There is no possible for platform_get_irq() to return 0,
and the return value of platform_get_irq() is more sensible
to show the error reason.

Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>