meta-ettus-core: Add package config to support mpm and liberio
meta-ettus-core: Add package config to support mpm and liberio

Add package config to support enabling MPMD and LIBERIO options
through PACKAGECONFIG[mpmd] and PACKAGECONFIG[liberio].

Signed-off-by: Sugandha Gupta <d84b5530ef1fc2430e5b91666d65ccc4e6d6f16e@ettus.com>
Signed-off-by: Moritz Fischer <16c4312f096cb05ec900643fe7a5f22f7761ab4a@ettus.com>

EttusResearch/meta-ettus,EttusResearch/meta-ettus,EttusResearch/meta-ettus,EttusResearch/meta-ettus,EttusResearch/meta-ettus,EttusResearch/meta-ettus