media: hantro: make irq names configurable

The i.MX8MQ bindings will use different IRQ names ("g1" instead of
"vdpu", and "g2"), so make them configurable. This also allows to
register more than two IRQs, which will be required for i.MX8MM support
later (it will add "h1" instead of "vepu").

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>