media: saa7134: Use devm_request_irq

The handled version of request_irq let us remove the free_irq and makes
smatch happier:

drivers/media/pci/saa7134/saa7134-alsa.c:1186 alsa_card_saa7134_create() warn: 'dev->pci->irq' from request_irq() not released on lines: 1186

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>