nilrt.inc: add virtualization to DISTRO_FEATURES
nilrt.inc: add virtualization to DISTRO_FEATURES

Starting with Sumo, meta-virtualization complains if the distro
feature is missing, since they made some their logic conditional on
it.

Signed-off-by: Ioan-Adrian Ratiu <7ec73abcfe099fc5574c01312b62768070c80980@ni.com>

ni/meta-nilrt,ni/meta-nilrt,ni/meta-nilrt,ni/meta-nilrt,ni/meta-nilrt