map_pci_memory: wait for kernel driver to release the device
map_pci_memory: wait for kernel driver to release the device

Starting with 4.5, the kernel returns EINVAL for mmap() if compiled
with CONFIG_IO_STRICT_DEVMEM=y. Unbinding the device is an
asynchronous operation. map_pci_memory() waits for EINVAL to disappear
or gives up after a timeout of 5 seconds.

# Conflicts:
#	src/lib/hardware/pci.lua

eugeneia/snabb,snabbco/snabb,snabbco/snabb,eugeneia/snabb,eugeneia/snabb,eugeneia/snabb,snabbco/snabb,snabbco/snabb,snabbco/snabb,eugeneia/snabb,snabbco/snabb,eugeneia/snabb,snabbco/snabb,eugeneia/snabb,eugeneia/snabb,snabbco/snabb