kernel/linux: remove igb_uio

kernel/linux: remove igb_uio

As decided in the Technical Board in November 2019,
the kernel module igb_uio is moved to the dpdk-kmods repository
in the /linux/igb_uio/ directory.

Minutes of Technical Board meeting:
https://mails.dpdk.org/archives/dev/2019-November/151763.html

Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Andrew Rybchenko <arybchenko@solarflare.com>
Acked-by: Jerin Jacob <jerinj@marvell.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>