media: hantro: Fix check for single irq

Some cores use only one interrupt and in such case interrupt name in DT
is not needed. Driver supposedly accounted that, but due to the wrong
field check it never worked. Fix that.

Fixes: 18d6c8b7

 ("media: hantro: add fallback handling for single irq/clk")
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>