igb_uio: fail and log if kernel lock down is enabled

igb_uio: fail and log if kernel lock down is enabled

When EFI secure boot is enabled, it is possible to lock down kernel and
prevent accessing device BARs and this makes igb_uio unusable.

Lock down patches are not part of the vanilla kernel but they are
applied and used by some distros already [1].

It is not possible to fix this issue, but intention of this patch is to
detect and log if kernel lock down enabled and don't insert the module
for that case.

The challenge is since this feature enabled by distros, they have
different config options and APIs for it. This patch is done based on
Fedora and Ubuntu kernel source, may needs to add more distro specific
support.

[1]
kernel.ubuntu.com/git/ubuntu/ubuntu-artful.git/commit/?id=99f9ef18d5b6
And a few more patches too.

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Luca Boccassi <bluca@debian.org>