libcurl: add wolfssl as an option for TLS

libcurl: add wolfssl as an option for TLS

Libcurl recipe allows selecting between various TLS backends. Users can
already select between several options but WolfSSL was missing. WolfSSL
is an efficient TLS library, it supports TLS 1.3 and is used in many
embedded systems.

Add WolfSSL to libcurl "SSL/TLS library to use" choice list when WolfSSL
package is enabled. When selected in the list, use libcurl
--with-wolfssl configure option. Explicitly set --without-wolfssl
when it is not selected.

Signed-off-by: Julien Grossholtz <julien.grossholtz@openest.io>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>