libpcre2: add it for newer vte

libpcre2: add it for newer vte

There are two major versions of the PCRE library. The newest version, PCRE2,
was released in 2015 and is at version 10.22.

The original, very widely deployed PCRE library, originally released in 1997,
is at version 8.40, and the API and feature set are stable, future releases
will be for bugfixes only. All new future features will be to PCRE2, not the
original PCRE 8.x series.

The newer vte depends on libpcre2, so add it.

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>