lib: add usb core driver

Add a new lib to manage a USB stack for a device profile
based on PCD handle.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Change-Id: I7971ec6d952edec3511157a198e6e5359df4346b
Reviewed-on: https://gerrit.st.com/c/mpu/oe/st/tf-a/+/177364


Reviewed-by: CITOOLS <smet-aci-reviews@lists.codex.cro.st.com>
Reviewed-by: Yann GAUTIER <yann.gautier@st.com>
Tested-by: Yann GAUTIER <yann.gautier@st.com>