Issue setting up the DPDK development with non-privileged user

[Dmitry Kozlyuk]

Hi Boris,

1. Tests on Ubuntu 20.04 kernel 5.4.0-96-generic
   show that CAP_DAC_OVERRIDE is missing from the list.
   Unfortunately, this capability guards quite a lot.

2. If the process lack privileges,
   it will see /proc/self/pagemap zero-filled.

I assume you understand that using physical addresses
allows to effectively bypass any OS restrictions.

Please tell if CAP_DAC_OVERRIDE helps, I will update the doc.