eal/freebsd: support option --base-virtaddr
According to our docs, only Linuxapp supports base-virtaddr option.
That is, strictly speaking, not true because most of the things
that are attempting to respect base-virtaddr are in common files,
so FreeBSD already *mostly* supports this option in practice.
This commit fixes the remaining bits to explicitly support
base-virtaddr option, and moves the arg parsing from EAL to common
options parsing code. Documentation is also updated to reflect
that all platforms now support base-virtaddr.
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>