media: staging/ipu7: convert to use pci_alloc_irq_vectors() API

pci_enable_msi() is a deprecated API, thus switch to use modern
pci_alloc_irq_vectors().

Fixes: b7fe4c00 ("media: staging/ipu7: add Intel IPU7 PCI device driver")
Signed-off-by: Bingbu Cao <bingbu.cao@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>